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Try Science at Home
​Cool Chemistry

Disappearing Gum

10/26/2021

1 Comment

 
What happens if you chew gum and chocolate at the same time?  You'll find out in this sweet candy science experiment while learning an important concept in chemistry: solubility.
Click and expand the tabs below to get started
What you'll need
  • Chewing gum - candy coated pieces like gum-balls or Chiclets are best, but any stick or piece of bubblegum will work.
  • Chocolate - milk chocolate like Hershey's Kisses or plain Halloween-sized candy bars are best.
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experimental procedure
  1. Chew the gum in your mouth for a minute or two.
  2. Take the gum out of your mouth (yes, really) and compare how it looks now compared to  how it looked before you chewed it.
  3. Put the gum back in your mouth, then also put a piece of chocolate in your mouth and chew them together. 
  4. After another minute or two take the gum (and any chocolate that may be left) out of your mouth.  What does it look like now?  Is it still sticky?
  5. Put it back in your mouth and keep chewing.  What happens to the gum?  If you have more chocolate add that to your mouth and continue chewing.  Can you make the gum disappear?

what's happening
This is a chemistry experiment, even though you are doing it in your mouth! It illustrates a very important concept in chemistry called solubility, which is the ability of one substance to dissolve another substance.  Chemists say that “like dissolves like” and this is an example of that.  If your gum was candy coated, like a Chiclet or gum-ball, you should have noticed that the candy coating dissolved or disappeared as soon as you began chewing.  This is because the candy coating was made of sugar, which easily dissolves in water (try adding a spoon full of table sugar to a glass of water and watch what happens), and the saliva in your mouth is mostly water.  Chemists would say that sugar is soluble in water.  Saliva and chewing are the first steps in digesting or breaking down your food into simpler components that your body can use for energy.

Your saliva does not dissolve the gum, however, because most modern chewing gums are made of a synthetic rubber (i.e. man-made, not natural), which is a type of oil-based polymer, such as  butadiene-styrene, vinyl acetate, or polyethylene (the same material in plastic grocery bags).  You may have already learned that oil (as well as oil-based substances) and water don't mix- they are not alike.  But chocolate does contain oil-based fatty substances, so the chocolate dissolves the gum.  Like dissolves like.  After adding the first piece of chocolate and chewing you should have noticed that the gum was much softer and stickier, and maybe much smaller than it was after you first chewed the gum alone.  If you add enough chocolate to the gum in your mouth (you may need 3 or 4 pieces) and continue chewing you should be able to make the gum disappear completely! 
variations and related activities
If you're not allergic to peanuts, try chewing a spoon full of peanut butter with your gum instead of chocolate.  Does the peanut butter also make the gum disappear?  Why do you think that is?

Instead of doing the entire experiment in your mouth, just chew the gum for a minute or two in your mouth, then put it in a cup or small bowl instead.  Add a couple spoonfuls of vegetable oil to the cup and use a spoon to stir and grind the gum.  Does it dissolve?  If not, add a little more vegetable oil.  Try repeating ths experiment with some other liquids.  Is gum more or less soluble in other liquids?

Solubility has it's limits, however, and you can easily test this.   Add one or two spoonfuls of sugar to a glass of water and observe what happens.  Does all of the sugar dissolve immediately?  Observe for a minute or two, has more dissolved?  Use a spoon tp stir the water and sugar.  Does it dissolve more easily?  Try adding more spoonfuls of sugar and stirring.  Does the sugar continue to dissolve?  Keep adding sugar until it will no longer dissolve in the water.  Now you have reached the solubility limit- the water simply can't hold any more sugar and we say it is saturated.  What would happen if you added more water to the glass?  Solubility also depends temperature.  With the help of an adult try repeating this experiment with warm or hot water.  Is sugar more soluble in hot water, i.e. can you make more spoonfuls of sugar dissolve?

Coming soon:

make rock candy
float letters off M&M's
pop rocks
dancing raisins
carbonated soft drinks
Lava Lamps
Dissolve egg shell in vinegar
Underwater fireworks (food coloring dissolves in water but not oil)
Oil-based and water-based paints
​
references and links to more information
Journal of Chemistry Education Classroom Activity #105. A Sticky Situation: Chewing Gum and Solubility 
  • https://pubs.acs.org/doi/pdf/10.1021/ed800135j
​
Learn more about solubility:
  • https://en.wikipedia.org/wiki/Solubility


Coming soon:

Saliva
​Digestion
​Solubility experiments


​Subject Tags
​
  • Food Chemistry
  • Kitchen Science
  • Oils
  • Polymers
  • ​Water

All Chemistry Subject Tags

All
Acid/Base Chemistry
Bubbles
Crystals
Density
Food Chemistry
Heat/Cold
Kitchen Science
Milk Chemistry
Oils
Phase/State Changes
Polymers
Soap
Water

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1 Comment

There's Metal in My Cereal!

3/22/2021

5 Comments

 


​Metals like iron and steel are used to make cars and ships and nails.  You may have also heard that you need iron-rich foods in your diet for good health; iron deficiency can lead to diseases like anemia.  But maybe you never realized that it's actually the same iron in each case.  That's right- you're eating exactly the same stuff found in nails every day, and in this experiment you will see it for yourself!



Este experimento está disponible en español
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Click and expand the tabs below to get started.
What you'll need
  • ​Small cups or bowls with tight-fitting lids (if you don't have cups with lids you can use any cup and just stir instead of shaking)
  • Zip-Lock or other small plastic bag
  • Plastic spoon or popsicle stick for stirring
  • Small neodymium (rare Earth) magnet(s), about the size and shape of a coin works best.  You should be able to find them in a hardware or department store.  An ordinary magnet will not work.  Some online suppliers.  [Note: neodymium magnets are very strong, so be careful to keep them away from any other magnets or metals, as they may pinch your fingers or skin.  They can also break easily producing sharp edges.]
  • Tape
  • Breakfast cereals (a nutritious or "healthy" brand like "Total" is best to start with, but you may want to try several different ones; look for cereals that list "Reduced Iron" or simply "Iron" in the ingredients, avoid those that list "Ferric Orthophosphate")
  • Water
  • Magnifying glass (optional)
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experimental procedure

  1. Tape your magnet to the bottom of your cup (on the outside).
  2. Add a few spoonfuls of dry cereal to your Zip-Lock bag, gently squeeze out most of the air and zip shut, then crush or smash the cereal into powder.
  3. Open the bag and fill your small cup mostly full with the crushed cereal.
  4. Add some water to the cereal in the cup and stir.  Add enough water to make a soupy mix, then attach the lid.  Make sure it's sealed tightly.
  5. Shake and mix the cereal in the cup for several minutes, holding the lid if necessary to make sure it doesn't come off.   If you don't have cups with lids you can use any cup and just stir instead of shaking.
  6. Carefully remove the lid and pour the cereal into another cup or bowl (don't throw it away yet, you may want to reuse it).
  7. Gently rinse the cup with water then look for tiny black particles or shavings that are stuck to the bottom of the cup near the magnet.  If you have a magnifying glass you can look very closely.  If you don't see any black particles try pouring the cereal mix back into the cup and shaking it for a few more minutes, then check again.  
  8. If you have another magnet and cup, repeat steps 1-7 with a different cereal to compare the amount of black shavings from each (be sure you use the same amount of cereal and shake the cup for the same amount of time).  If you only have one magnet or cup you can carefully remove the magnet without spilling the shavings, then pour them into another cup on onto a piece of paper and set aside (if you can dry them you might try sticking them onto another piece of tape).  Rinse you cup and then repeat steps 1-7.
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what's happening
Iron is a crucial component of a balanced diet (there should actually be enough iron in your body to make one or two small nails), but some people might not consume enough iron naturally to sustain themselves.  Because of this, many food manufacturers add iron to some foods to boost the average daily intake of this important mineral.  Some  foods may use a chemical form like ferric orthophosphate (FePO4) or ferrous sulfate (FeSO4), but most cereals simply use elemental (i.e. the pure atom) iron (Fe), also called "Reduced Iron".  

The iron you see in your cereal is elemental iron- actual metallic iron filings or shavings similar to the little flakes you might see come off of a steel wool pad when you squeeze or rub it, just much smaller.  That's right, you're eating metal in the morning!  But not to worry, acids in your digestive tract can change this metallic iron into a form that is easily absorbed and used by your body.  [Note: if you don't see any iron particles in this experiment you probably have a cereal that add one of the chemical forms listed above, so try a different cereal instead.]

These very tiny metal particles are mixed into the rest of the cereal ingredients, which is why you don't normally see them, but a magnet will attract these small iron filings that are present in the cereal, separating them from the other cereal components which are not attracted to the magnet (there's more information about magnetism in the reference links below).  Crushing the cereal and mixing it with water makes it much easier to separate the iron.  By the way, this is also why you need to use a wooden popsicle stick or plastic spoon to stir in Step 8 of the procedure above (if your cup doesn't have a lid).  Most metal spoons are made of steel, which contains a lot of iron and therefore will also be attracted to your magnet (although some types of steel are actually not very magnetic at all).

​Separating iron from cereal requires a powerful magnetic field, which is why we need to use a strong neodymium magnet, which is actually made from the elements neodymium, iron and boron (Nd2Fe14B).  Neodymium is rarely found in nature, so these magnets are sometimes called Rare Earth magnets.  Neodymium magnets are usually plated with a thin layer of another metal like nickel so they look like they're metal, but they are actually a type of ceramic.  Ceramic materials are similar to glass, so these magnets are fragile and can shatter or break quite easily, often producing sharp edges, if you allow them to slam together.  Because of this as well as their strength they must be handled very carefully.

Some breakfast cereals contain much more iron that other cereals.  You can find out how much iron any cereal contains by reading the "Nutrition Facts" labels on the side of the box (like the photo above).  For example, "Total" cereal contains 100% of the recommended daily iron allowance, while "Shredded Wheat" contains only 8% - this is why you should see more iron filings from the Total cereal.  Test several different cereals, does the amount of iron you see agree with the information on the labels?  Is it important that you use the same amount of each cereal and shake it for the same length of time?  Is it important to use the same amount of water?  Why or why not?
​
variations and related activities
After you have separated the iron from the cereal and water mix and rinsed the cup with water, carefully remove the magnet from the bottom of the cup.  Be sure not to tip the cup as once the magnet is removed the iron particles will be free to move.  Add a little bit of water to the cup and gently stir or swirl the cup to mix the iron particles.  Now hold the magnet near the sides or bottom of the cup and observe how the tiny iron particles move.  Try holding the magnet in different positions.  How does this affect the movement and orientation of the iron particles?  If you're careful you may be able to observe the shape of the magnetic field lines that surround the magnet.  You can also try this with a little bit of vegetable or baby oil instead of water in the cup [first tape the magnet to the bottom of the cup again to attract and pin all the iron, then carefully dump out the water and gently dry the cup without disturbing the iron particles, then add the oil].  How does the oil affect the motion of the iron particles?

If you hold your magnet near a flake of piece of the cereal, does it move?  What if you crush the cereal into smaller pieces?  Try floating a piece of cereal in a bowl of water, then holding the magnet very close.  Does it move now?

Another way to do this experiment is to place your magnet inside a small balloon, squeeze out any air inside, then tie it.  Now simply drop the balloon into your bowl of mashed cereal and water mixture, attach the lid and shake several minutes as before.  Open the lid, remove the balloon and rinse it with water to see the iron filings stuck to the balloon.

If you want to try another cool science experiment with your left over cereal (although it has nothing to do with iron or metal), check out the "Cheerios Effect" (see reference link below).  As the name suggests, it works best with Cheerios, but try it with other cereals too.
​
 
References and links to more information
Other variations of this experiment:
  • https://mocomi.com/iron-in-cereal/
  • https://www.scientificamerican.com/article/get-the-iron-out-of-your-breakfast-cereal-bring-science-home/
  • https://www.stevespanglerscience.com/lab/experiments/eating-nails-for-breakfast/
  • https://www.sciencebuddies.org/science-fair-projects/project-ideas/BioChem_p027/biotechnology-techniques/iron-in-breakfast-cereal
  • https://www.education.com/science-fair/article/iron-in-breakfast-cereal/​

Why iron is so important for your body:
  • https://www.cdc.gov/nutrition/InfantandToddlerNutrition/vitamins-minerals/iron.html
  • https://www.eatright.org/food/vitamins-and-supplements/types-of-vitamins-and-nutrients/iron
  • https://www.herzindagi.com/diet-nutrition/top-foods-high-iron-why-iron-is-important-for-body-article-158578
​
​Which breakfast cereals have the most iron:
  • https://foodwithiron.com/breakfast-cereals-high-in/
  • https://tools.myfooddata.com/nutrient-ranking-tool.php?nutrient=Iron&foodgroup=Breakfast-Cereals&sortby=Highest

Iron and magnetism (ferromagnetism):
  • https://sciencing.com/why-does-magnet-attract-iron-4572511.html
  • https://en.wikipedia.org/wiki/Ferromagnetism
  • https://www.thoughtco.com/not-all-iron-is-magnetic-3976017

Magnetic field lines:
  • https://www.thoughtco.com/magnetic-field-lines-4172630

The Cheerios Effect (and how it affects bugs that walk on water):
  • https://ed.ted.com/best_of_web/8HDeZKFr#watch
¡Hay metal en mi cereal!  (en español)
​Los metales como el hierro y el acero se utilizan para fabricar automóviles, barcos y clavos. Es posible que también haya escuchado que necesita alimentos ricos en hierro en su dieta para una buena salud; la deficiencia de hierro puede provocar enfermedades como la anemia. Pero tal vez nunca se dio cuenta de que en realidad es el mismo hierro en cada caso. Así es, estás comiendo exactamente lo mismo que se encuentra en las uñas todos los días, ¡y en este experimento lo verás por ti mismo!
Lo que necesitarás
  • Tazas o tazones pequeños con tapas ajustadas
  • Zip-Lock u otra bolsa de plástico pequeña
  • Cuchara de plástico o palito de paleta para revolver
  • Los imanes pequeños de neodimio (tierras raras), del tamaño y la forma de una moneda, funcionan mejor. Debería poder encontrarlos en una ferretería o una tienda por departamentos. Un imán ordinario no funcionará. Algunos proveedores en línea. [Nota: los imanes de neodimio son muy fuertes, así que tenga cuidado de mantenerlos alejados de otros imanes o metales, ya que pueden pellizcarle los dedos o la piel. También pueden romperse fácilmente produciendo bordes afilados.]
  • Cinta
  • Cereales para el desayuno (una marca nutritiva o "saludable" como "Total" es mejor para empezar, pero es posible que desee probar varios diferentes; busque cereales que incluyan "Hierro reducido" en los ingredientes, evite los que indiquen "Férrico Ortofosfato ")
  • Agua
  • Lupa (opcional)
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Procedimiento experimental
  1. Pegue con cinta adhesiva su imán al fondo de su taza (en el exterior).
  2. Agregue algunas cucharadas de cereal seco a su bolsa Zip-Lock, exprima suavemente la mayor parte del aire y cierre la cremallera, luego triture o triture el cereal en polvo.
  3. Abra la bolsa y llene su taza pequeña casi completamente llena con el cereal triturado.
  4. Agregue un poco de agua al cereal en la taza y revuelva. Agregue suficiente agua para hacer una mezcla espesa, luego coloque la tapa. Asegúrate de que esté bien sellado.
  5. Agite y mezcle el cereal en la taza durante varios minutos, sosteniendo la tapa si es necesario para asegurarse de que no se desprenda.  Si no tiene una tapa para su taza, puede simplemente revolver la mezcla de cereal / agua con un palito de helado o una cuchara de plástico, pero probablemente tomará mucho más tiempo separar las virutas negras.
  6. Retire con cuidado la tapa y vierta el cereal en otra taza o tazón (no lo tire todavía, es posible que desee reutilizarlo).
  7. Enjuague suavemente la taza con agua y luego busque pequeñas partículas negras o virutas que estén pegadas al fondo de la taza cerca del imán. Si tiene una lupa, puede mirar muy de cerca. Si no ve ninguna partícula negra, intente verter la mezcla de cereal nuevamente en la taza y agitarla durante unos minutos más, luego vuelva a verificar.
  8. Si tiene otro imán y una taza, repita los pasos 1-7 con un cereal diferente para comparar la cantidad de virutas negras de cada uno (asegúrese de usar la misma cantidad de cereal y agite la taza durante la misma cantidad de tiempo). Si solo tiene un imán o una taza, puede quitar con cuidado el imán sin derramar las virutas, luego verterlas en otra taza sobre un pedazo de papel y dejar a un lado (si puede secarlas, puede intentar pegarlas en otro trozo de cinta adhesiva). ). Enjuague su taza y luego repita los pasos 1-7.
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QUÉ ESTA PASANDO
El hierro es un componente crucial de una dieta equilibrada (en realidad, debería haber suficiente hierro en su cuerpo para hacer una o dos uñas pequeñas), pero es posible que algunas personas no consuman suficiente hierro de forma natural para mantenerse. Debido a esto, muchos fabricantes de alimentos agregan hierro a algunos alimentos para aumentar la ingesta diaria promedio de este importante mineral. Algunos alimentos pueden usar una forma química como el ortofosfato férrico (FePO4) o el sulfato ferroso (FeSO4), pero la mayoría de los cereales simplemente usan hierro (Fe) elemental (es decir, el átomo puro), también llamado "Hierro reducido". 
 
El hierro que ve en su cereal es hierro elemental, limaduras o virutas de hierro metálico reales similares a las pequeñas escamas que puede ver salir de una almohadilla de lana de acero cuando la aprieta o frota, pero mucho más pequeñas. Así es, ¡estás comiendo metal por la mañana! Pero no se preocupe, los ácidos en su tracto digestivo pueden cambiar este hierro metálico a una forma que su cuerpo absorbe y utiliza fácilmente. [Nota: si no ve ninguna partícula de hierro en este experimento, probablemente tenga un cereal que agregue una de las formas químicas mencionadas anteriormente, así que pruebe con un cereal diferente en su lugar.] 
 
Estas diminutas partículas de metal se mezclan con el resto del ingredientes de los cereales, por lo que normalmente no los ve, pero un imán atraerá estas pequeñas limaduras de hierro que están presentes en el cereal, separándolos de los otros componentes del cereal que no son atraídos por el imán (hay más información sobre el magnetismo en los enlaces de referencia a continuación). Triturar el cereal y mezclarlo con agua hace que sea mucho más fácil separar el hierro. Por cierto, esta es también la razón por la que debe usar un palito de paleta de madera o una cuchara de plástico para revolver en el Paso 8 del procedimiento anterior (si su taza no tiene tapa). La mayoría de las cucharas de metal están hechas de acero, que contiene mucho hierro y, por lo tanto, también se sentirán atraídas por su imán (aunque algunos tipos de acero en realidad no son muy magnéticos).

​La separación del hierro del cereal requiere un campo magnético potente, por lo que necesitamos utilizar un imán de neodimio potente, que en realidad está hecho de los elementos neodimio, hierro y boro (Nd2Fe14B). El neodimio rara vez se encuentra en la naturaleza, por lo que estos imanes a veces se denominan imanes de tierras raras. Los imanes de neodimio generalmente se recubren con una capa delgada de otro metal como el níquel para que parezcan de metal, pero en realidad son un tipo de cerámica. Los materiales cerámicos son similares al vidrio, por lo que estos imanes son frágiles y pueden romperse o romperse con bastante facilidad, a menudo produciendo bordes afilados, si permite que se golpeen entre sí. Debido a esto, así como a su fuerza, deben manejarse con mucho cuidado. 
 
Algunos cereales para el desayuno contienen mucho más hierro que otros cereales. Puede averiguar cuánto hierro contiene cualquier cereal leyendo las etiquetas de "Información nutricional" al costado de la caja (como la foto de arriba). Por ejemplo, el cereal "Total" contiene el 100% de la cantidad diaria recomendada de hierro, mientras que el "Trigo desmenuzado" contiene solo el 8%; es por eso que debería ver más limaduras de hierro del cereal Total. Pruebe varios cereales diferentes, ¿la cantidad de hierro que ve coincide con la información de las etiquetas? ¿Es importante que use la misma cantidad de cada cereal y lo agite durante el mismo tiempo? ¿Es importante utilizar la misma cantidad de agua? ¿Por qué o por qué no?
variaciones y actividades relacionada
Próximamente
REFERENCIAS Y ENLACES A MÁS INFORMACIÓN
Otras variaciones de este experimento:
  • https://mocomi.com/iron-in-cereal/
  • https://www.scientificamerican.com/article/get-the-iron-out-of-your-breakfast-cereal-bring-science-home/
  • https://www.stevespanglerscience.com/lab/experiments/eating-nails-for-breakfast/
  • https://www.sciencebuddies.org/science-fair-projects/project-ideas/BioChem_p027/biotechnology-techniques/iron-in-breakfast-cereal
  • https://www.education.com/science-fair/article/iron-in-breakfast-cereal/​

Por qué el hierro es tan importante para tu cuerpo:
  • https://www.cdc.gov/nutrition/InfantandToddlerNutrition/vitamins-minerals/iron.html
  • https://www.eatright.org/food/vitamins-and-supplements/types-of-vitamins-and-nutrients/iron
  • https://www.herzindagi.com/diet-nutrition/top-foods-high-iron-why-iron-is-important-for-body-article-158578
​
​Qué cereales para el desayuno tienen más hierro:
  • https://foodwithiron.com/breakfast-cereals-high-in/
  • https://tools.myfooddata.com/nutrient-ranking-tool.php?nutrient=Iron&foodgroup=Breakfast-Cereals&sortby=Highest

Hierro y magnetismo (ferromagnetismo):
  • https://sciencing.com/why-does-magnet-attract-iron-4572511.html
  • https://en.wikipedia.org/wiki/Ferromagnetism
  • https://www.thoughtco.com/not-all-iron-is-magnetic-3976017

Líneas de campo magnético:
  • https://www.thoughtco.com/magnetic-field-lines-4172630

El efecto Cheerios (y cómo afecta a los insectos que caminan sobre el agua):
  • https://ed.ted.com/best_of_web/8HDeZKFr#watch

Subject Tags

  • Food Chemistry
  • Kitchen Science

All Chemistry Subject Tags

All
Acid/Base Chemistry
Bubbles
Crystals
Density
Food Chemistry
Heat/Cold
Kitchen Science
Milk Chemistry
Oils
Phase/State Changes
Polymers
Soap
Water

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5 Comments

Baking with Gas

3/22/2021

0 Comments

 
Have you ever wondered what makes a flour dough rise, or why there are lots of little holes inside your bread or pancakes?  And what is the difference between baking soda and baking powder?  Well, you're in luck because that's what this experiment is all about.

Este experimento está disponible en español

Click and expand the tabs below to get started.​
what you'll need
  • All-purpose flour
  • Baking powder
  • Baking soda
  • Water (room temperature)
  • Vinegar or lemon juice
  • 3 small cups (plastic is fine).
  • Teaspoon​ for measuring
  • Small spoons or popsicle sticks for stirring
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experimental procedure
  1. Place about 1 teaspoon of baking powder in one of your small cups.  
  2. Place about 1 teaspoon of baking soda in another small cup.
  3. Place about 1 teaspoon of water into each of the cups from Steps 1 and 2 and stir each with a clean spoon or popsicle stick.
  4. Observe closely what is happening in each of the cups.  Do you see any bubbles?  Do you hear anything?
  5. Add about 1 teaspoon of vinegar or lemon juice to the baking soda cup.  Do you observe anything happening now?
  6. Place about 1 teaspoon of flour in a third clean cup.  Add about 1 teaspoon of baking powder and mix thoroughly with a clean spoon or popsicle stick.
  7. Add about 2 teaspoons of water to the flour and baking powder in the third cup and stir.  
  8. Observe closely what is happening.
what's happening
Baking soda is the common name for sodium bicarbonate, a type of substance or chemical called a base.  When it is mixed with water is simply dissolves with no reaction.  Baking powder, however, contains not only sodium bicarbonate but also another type of chemical called an acid (or sometimes two different acids).  When these chemicals dissolve in water the base sodium bicarbonate reacts with the acid.  This is called a chemical reaction because it results in the creation of one of more new and completely different substances.  Acids and bases often react with each other.  In this reaction the new substance is a gas called carbon dioxide, which is the tiny bubbles that you observe.  You can also hear them popping as the gas escapes.  

The baking soda did not react because there was no acid present, but if you add a little acid like vinegar or lemon juice then you will get a reaction that also produces carbon dioxide gas- in fact, lots of gas bubbles and foam!  You may have done this reaction before to make the famous vinegar and baking soda volcano!

Chemical reactions like this are used in baking breads, pancakes, cookies and other foods.  When mixed with flour and water to make a dough the gas bubbles are trapped inside and cause the dough to inflate like a balloon or rise.  That's what happened in the third cup when you added flour.  ​This is called leavening, and ingredients like baking powder or baking soda are call leavening agents.  Baking this dough at high temperature in an oven causes the flour molecules to lock together into a firm solid structure giving us something good to eat!  Meanwhile the carbon dioxide bubbles eventually pop and the gas escapes, leaving behind the tiny little holes we see in baked goods.
​
variations and related activities
Some recipes use baking soda instead of baking powder because there is some other ingredient already present that provides the acid needed to produce the gas.  Some recipes even use both baking soda and baking powder to produce carbon dioxide at different times during the baking.  

Most baking powder used today is "Double Acting Baking Powder".  It contains two different acids, one which reacts as soon as the water is added and a second acid that doesn't react until it reaches a certain high temperature.  This causes the dough to rise twice- once when it is first mixed then again during baking in the oven.

You can continue this activity in a tasty way with a simple homemade pancake recipe (see link below), and make it into a real experiment by making some pancakes without the baking powder and baking soda.  How do these pancakes compare to the normal ones?  What if you leave out one of the other ingredients? 

Pizza dough and some other baked goods use a very different ingredient- yeast- to make the dough rise.  Yeasts are actually tiny living organisms called fungi that "eat" sugars and "burp" carbon dioxide gas.  Check out the references below if you would like to experiment with yeast.
 
references and links to more information
What purpose do the various ingredients serve in baking?:
  • https://kidpillar.com/science-of-baking-for-kids/
  • https://washingtonparent.com/teach-kids-science-through-baking/
  • http://www.bakingscience.com

Try a pancake science recipe and experiment:
  • https://science-u.org/experiments/pancake-science.html

Other baking science experiments:
  • https://www.sciencebuddies.org/science-fair-projects/project-ideas/experiment-with-baking

More baking Soda experiments:
  • https://babbledabbledo.com/5-easy-baking-soda-science-projects-your-kids-will-love/
  • https://www.steampoweredfamily.com/activities/baking-soda-and-vinegar-experiments/

Yeast science and baking experiments:
  • https://kidsdiscover.com/teacherresources/science-of-yeast-for-kids/
  • https://www.education.com/science-fair/article/biology_foamy/
  • https://www.nationalgeographic.com/history/article/funky-science-yeast-gassy-microbe-behind-coronavirus-pandemic-bread
​
Hornear con gas (en español)
​¿Alguna vez te has preguntado qué hace que la masa de harina se eleve o por qué hay muchos pequeños agujeros dentro de tu pan o panqueques? ¿Y cuál es la diferencia entre bicarbonato de sodio y levadura en polvo? Bueno, estás de suerte porque de eso se trata este experimento.
Lo que necesitarás
  • Harina para todo uso
  • Levadura en polvo
  • Bicarbonato de sodio
  • Agua (temperatura ambiente)
  • Vinagre o jugo de limón
  • 3 tazas pequeñas (de plástico está bien).
  • Cucharadita para medir
Cucharas pequeñas o palitos de helado para revolver
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Procedimiento experimental
  1. Coloque aproximadamente 1 cucharadita de polvo de hornear en una de sus tazas pequeñas.
  2. Coloque aproximadamente 1 cucharadita de bicarbonato de sodio en otra taza pequeña.
  3. Coloque aproximadamente 1 cucharadita de agua en cada una de las tazas de los Pasos 1 y 2 y revuelva cada una con una cuchara limpia o un palito de paleta.
  4. Observa de cerca lo que sucede en cada uno de los vasos. ¿Ves burbujas? ¿Escuchas algo?
  5. Agregue aproximadamente 1 cucharadita de vinagre o jugo de limón a la taza de bicarbonato de sodio. ¿Observa algo que está sucediendo ahora?
  6. Coloque aproximadamente 1 cucharadita de harina en una tercera taza limpia. Agregue aproximadamente 1 cucharadita de polvo de hornear y mezcle bien con una cuchara limpia o un palito de paleta.
  7. Agregue aproximadamente 2 cucharaditas de agua a la harina y el polvo de hornear en la tercera taza y revuelva.
  8. Observe de cerca lo que está sucediendo.
Qué esta pasando
Bicarbonato de sodio es el nombre común del bicarbonato de sodio, un tipo de sustancia o químico llamado base. Cuando se mezcla con agua, simplemente se disuelve sin reacción. Sin embargo, el polvo de hornear contiene no solo bicarbonato de sodio, sino también otro tipo de químico llamado ácido (oa veces dos ácidos diferentes). Cuando estos productos químicos se disuelven en agua, el bicarbonato de sodio básico reacciona con el ácido. Esto se llama reacción química porque da como resultado la creación de una o más sustancias nuevas y completamente diferentes. Los ácidos y las bases a menudo reaccionan entre sí. En esta reacción, la nueva sustancia es un gas llamado dióxido de carbono, que son las diminutas burbujas que observas. También puede escucharlos estallar cuando el gas se escapa. 
 
El bicarbonato de sodio no reaccionó porque no había ácido presente, pero si agrega un poco de ácido como vinagre o jugo de limón, obtendrá una reacción que también produce dióxido de carbono, de hecho, ¡muchas burbujas de gas y espuma! ¡Es posible que hayas hecho esta reacción antes para hacer el famoso volcán de vinagre y bicarbonato de sodio! 
 
Las reacciones químicas como esta se utilizan para hornear panes, panqueques, galletas y otros alimentos. Cuando se mezcla con harina y agua para hacer una masa, las burbujas de gas quedan atrapadas en el interior y hacen que la masa se infle como un globo o se eleve. Eso es lo que sucedió en la tercera taza cuando agregaste harina. ¡Hornear esta masa a alta temperatura en un horno hace que las moléculas de harina se bloqueen en una estructura sólida y firme que nos da algo bueno para comer! Mientras tanto, las burbujas de dióxido de carbono eventualmente explotan y el gas escapa, dejando atrás los pequeños agujeros que vemos en los productos horneados.
Variaciones y actividades relacionadas
Algunas recetas usan bicarbonato de sodio en lugar de polvo de hornear porque ya hay algún otro ingrediente presente que proporciona el ácido necesario para producir el gas. Algunas recetas incluso usan bicarbonato de sodio y polvo de hornear para producir dióxido de carbono en diferentes momentos durante la cocción. 
 
La mayor parte del polvo de hornear que se usa hoy en día es el "polvo de hornear de doble acción". Contiene dos ácidos diferentes, uno que reacciona tan pronto como se agrega el agua y un segundo ácido que no reacciona hasta que alcanza una cierta temperatura alta. Esto hace que la masa suba dos veces, una cuando se mezcla por primera vez y luego nuevamente durante la cocción en el horno. 
 
Puede continuar este experimento de una manera sabrosa con una receta de panqueques casera simple (link abajo).

La masa de pizza y algunos otros productos horneados utilizan un ingrediente muy diferente, la levadura, para hacer que la masa suba. Las levaduras son en realidad pequeños organismos vivos llamados hongos que "comen" azúcares y "eructan" gas de dióxido de carbono. Consulte las referencias a continuación si desea experimentar con levadura

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  • Acid/Base Chemistry
  • Food Chemistry
  • Kitchen Science​




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Baking Crackers

8/17/2020

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Think about a nice, creamy pat of butter, sitting on a freshly baked, homemade cracker!  Is your mouth watering yet?  There is a surprising amount of science to be found in the kitchen, so let’s take a look and see what we can learn!

​You can also make your own butter to put on your crackers!

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what you'll need
  • 1 1/2 cups all-purpose flour
  • 4 tablespoons butter
  • 1/4 cup water
  • 1 tablespoon honey
  • Mixing bowl
  • Measuring cups and spoons
  • Butter knife and spoon
  • Cookie or baking sheet
  • Rolling pin (optional)
  • Oven and Hot pads
experimental procedure
  1. Preheat the oven to 400 degrees Fahrenheit.  Then,
  2. Put 1 1/4 cups of flour in the big bowl.  Be sure to fill the cup up to the proper mark, and then level it off, because if we use too much flour, the dough will not stick together.
  3. Cut up the butter into little pieces, and drop it in the flour.
  4. Use your hands to squish the flour and the butter together, until the mixture is crumbly.  The smaller the chunks of butter are, the better the crackers will be.
  5. Add the water and the honey.  Squish the mixture around again.  You want to end up with a squishy, sticky ball of dough with very few (if any) recognizable lumps of butter in it.
  6. Dust your cookie sheet with a little bit of flour (less than ¼ cup).  Also, put some flour on your hands, and rub your hands over the rolling pin, if you are using one.
  7. Put the dough on the cookie sheet and smush it down flat with your hands.  If you are using a rolling pin, use it to roll out the dough so it is very flat.  When you smush the dough straight down with your hands, you should barely feel it move.
  8. Cut the dough into shapes (squares, rectangles, triangles, etc.) with the butter knife.
  9. Have a grown up put the cookie sheet in the oven, and set the timer for ten minutes.
  10. After 10 minutes, have a grown up take the cookie sheet out of the oven, and let the crackers cool.  They will not be very crispy at first, but they will get a little more crispy as they cool and dry.​

what's happening
Let’s take a closer look at our crackers.  Do they look poofy at all to you?  Or are they pretty flat?  They should be flat, because we didn’t add any leavening to them.  Leavening is the cooking term for any ingredient that will make things that you bake poofy.  Things like baking powder and baking soda make bread and cakes rise because they react with other ingredients in the dough to make carbon dioxide bubbles.  The holes that we see when we look at a piece of bread are the outsides of those carbon dioxide bubbles.  The carbon dioxide escapes into the air, and we have a delicious piece of bread.  However, in this case, we didn’t want the crackers to be poofy, so we didn’t put anything in that would make the bubbles.  So, our crackers should be flat and delicious!
​

variations and related activities
Coming soon.
references and links to more information
Coming soon.

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  • Kitchen Science​

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I Can't Believe It IS Butter!

8/17/2020

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You won't believe how easy it is to make your own butter simply by shaking a cup of heavy whipping cream, which comes from milk.  Give it a try- and you even get to eat this experiment when you're done!

Click tabs below to get started
what you'll need
  • Heavy Whipping Cream
  • Small jar or plastic container with a tight fitting lid
  • Table salt
  • Cold water
  • Knife or popsicle stick
  • Some bread or crackers if you want to eat your butter

​For whipped cream (optional):
  • Mixing bowl
  • Wire whisk or electric mixer
  • Powdered sugar

Be sure to ask your mom, dad or another adult to help-you can share your butter with them.
experimental procedure
  1. Pour some heavy whipping cream into a small jar or plastic container.  For just yourself one or two tablespoons of cream is fine, so be sure to use a very small jar.  If your jar is a larger you can use more, but either way, fill the jar only about half full so you have plenty of room. 
  2. Make sure the lid is closed tightly, then shake the jar vigorously.  Use slow, deliberate strokes, almost like you are trying to throw the jar as hard as you can but then stopping your arm suddenly (don't let go!)  The harder you shake, the quicker you will make your butter. 
  3. At first you should hear (and feel) the cream sloshing back and forth with each stroke, but after a minute or two you won't hear or feel anything moving inside.  If you like, carefully open the lid a little and peek inside. You should see a thick, creamy white foam.  This is whipped cream- taste a little with your fingertip if you like (of course there is no sugar, so it won't be sweet). 
  4. Carefully replace the lid, making sure it is very tight and won't leak, and continue shaking as before.  It feels like nothing is happening, but stick with it.
  5. After a few more minutes you will finally hear a liquid begin to slosh around again, and this time you should also feel a thud as something solid slams against the jar.  Shake it a few more times very hard.
  6. Carefully open the lid and look inside.  You should see a clump or perhaps a ball of solid butter as well as a thin milky liquid. The butter may be white or yellow.  The liquid is buttermilk. Taste a little of the buttermilk if you like.
  7. Carefully pour off all of the buttermilk into another jar or cup if you want to save it for cooking or baking (buttermilk pancakes or biscuits), otherwise just pour it down the sink.  Use your lid as you pour to make sure you don't lose the butter you've worked so hard to make.
  8. Add cold water to the jar of butter (about 3/4 full), tightly close the lid and shake it vigorously for about a minute to rinse your butter.  This time you don't need to shake slow and hard, normal shaking is fine. 
  9. Carefully open the lid and pour off all the water as before.  Add more cold water and repeat one or two more times until the rinse water is clear.  If you like, you can also use your knife or popsicle stick to stir and knead the butter to rinse it even more thoroughly.

Once you finish rinsing your butter, remove all the water and taste it on some bread or a cracker.  Most butter you find in the grocery store has salt added, but your butter is unsalted (sometimes called sweet butter).  If you don't like the taste, add a pinch of salt.
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Additional Optional Experimental Procedure:

You can also make your own real whipped cream.

  1. Chill your of heavy whipping cream in the refrigerator (or even the freezer for an hour or so) so that it is very cold. 
  2. Pour one or two cups of chilled cream into a small mixing bowl.
  3. Add about 1/4 cup of powdered sugar per cup of cream.  You may also want to add a little vanilla extract or lemon juice for flavor.
  4. Use a wire whisk or electric mixer to whip the cream very quickly for a minute or two or until nice and fluffy.  Don't over-whip it or you will get butter again!
  5. Taste your whipped cream!​​
what's happening
Butter is very interesting scientifically.  We  used cream to make butter, but where does cream come from?  Cream comes from cows.  It is part of the milk that a cow gives.  It has a lot of fat in it.  Fat occurs in pieces called molecules.  These molecules like to stick together in big clumps, but at the dairy they homogenized the milk to keep the fat and everything else all mixed up well.  When you shake the cream, however, the molecules which were floating around start sticking to each other.  When enough of them stick together they won't float or stay mixed up any more and you have butter!

​
more detailed explanation
Picture
You've probably heard that oil and water don't mix, but milk is in fact a mixture of many different components, including sugars, proteins, fats and yes, water.  [Fats and oils are basically similar molecules, also often called lipids, and made of smaller building blocks called fatty acids.  Although fat, oil and lipid are often used to refer to fats, "oil" generally refers to a fat that is liquid at normal room temperature and "fat" is solid at room temperature.]  The oil or fat in milk can mix with water without separating because they form into little globules sort of like water balloons.  The fat is inside a thin skin or membrane which helps attract water somewhat, and because fat is less dense than water, the globules float and form what's called a colloidal suspension or emulsion.  The smaller the globules, the easier it is for them to remain emulsified, but if they are too large they will separate and float to the surface.  Years ago before milk was homogenized, the fat globules would float to the top and form a layer called the cream, which contained most of the milk's fat.  Homogenization breaks up the larger globules into smaller ones, which, along with the milk proteins that then help form a stronger globule membrane, prevent this separation.  The cream you buy at the grocery store is separated at the dairy and then homogenized to keep the fat suspended in the liquid.  Heavy whipping cream means that it has a very high fat content, 36-40% (normal cream is about 30% fat, while Half & Half is 12% and whole milk 3.5% fat).  Butter is essentially pure milk fat.

In our heavy cream, the fat globules are still emulsified, or suspended in the water along with some protein and sugar.  If we shake the cream though, the globules will begin to crash into one another and pop or burst their membranes.  When this happens the fat molecules spill out and clump together with other fat molecules.  At first as this happens the fat traps a lot of air and forms bubbles or foam, which is the whipped cream.  The more you shake it, however, the more bubbles pop and the more densely the fat clumps become until they can no longer remain suspended in the water, and they separate completely.  This is the butter, and the remaining liquid, mostly water and proteins, is called buttermilk. 
​
The butter you make is not only good to eat, but will stay fresh for a long time, especially if it is thoroughly rinsed of all the milk liquid, since the milk can spoil.  Adding sugar to the whipped cream not only sweetens and thickens it, but helps prevent the fat bubbles from popping so that it will stay a light fluffy foam much longer.

variations and related activities
Try using cold heavy whipping cream to make butter.  Try warm cream.  Does it take more or less shaking to get to butter?  How do you think temperature affects this process?  If you like these milk science activities, you can also try our Milk Fireworks experiment, as well as making cottage cheese and glue (see link below) from milk.
references and links to more information
Others versions of this activity:
  • https://www.sfi.ie/site-files/primary-science/media/pdfs/col/sci_at_home_make_butter.pdf
  • http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p050.shtml#summary
  • http://foodformyfamily.com/recipes/food-science-camp-how-to-make-butter
  • http://www.makeandtakes.com/edible-science-experiment-making-butter-whipped-cream
  • http://www.scientificamerican.com/article/bring-science-home-butter-emulsion/

Experiment with the temperature of the cream:
  • http://www.scientificamerican.com/article/bring-science-home-shaking-butter/

Learn more about milk chemistry:
  • https://www.uoguelph.ca/foodscience/book-page/milk-structure

What is homogenized milk?:
  • milklife.com/articles/nutrition/what-homogenized-milk

Whipped cream as a science fair project:
  • https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p022/cooking-food-science/fresh-whipped-cream-that-lasts#summary
  • http://observationalgastrophysics.blogspot.com/2010/03/by-naveen-whipped-cream-has-been-on-my.html

What happens when whipped cream comes out of a can?:
  • https://science.nasa.gov/science-news/science-at-nasa/2008/25apr_cvx2/​

You can also make glue from milk:
  • http://www.science-sparks.com/2012/02/06/make-glue-from-milk/

​

Subject Tags
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  • Food Chemistry
  • Kitchen Science
  • ​Milk Chemistry

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A Fizzy Lava Lamp

6/30/2020

1 Comment

 


​This bubbly experiment combines principles of chemistry, density and buoyancy to create a colorful Lava Lamp look-alike that may be even more fun than the real thing!
Click and expand the tabs below to get started.
Picture
What you'll need
  • Tall plastic beverage cup or jar
  • Vegetable oil
  • Food colors
  • Alka-Seltzer tablets (or equivalent)