The Chemistry of Making Ice Cream

IntroductionI chose to figure out the chemistry of ice cream because it’s a sweet, fun treat that everyone can enjoy. The process of making ice cream interested me and once I found out that rock salt was a main component, I decided to not only look up how ice cream is made but why rock salt is used as well. The activity listed below is a great tool to see rock salt in action. Plus it’s a fun thing to do when it’s warm outside.

Composition of ...

What You Will Need:

1 Tablespoon of Sugar

½ Cup of Milk

¼ Teaspoon of Vanilla

6 Tablespoons of Rock Salt

1 Pint Size Storage Bag

1 Gallon Size Storage Bag

2 Trays of Ice Cubes

Sugar: Table sugar is made of Sucrose which is made up of Carbon, Hydrogen, and Oxygen atoms.

Milk: 87% of milk is made up of water. The rest is distributed with various forms of carbohydrates, fat, protein, vitamins,and minerals.


Vanilla: Vanilla contains vanillin which is the major component. It also contains ethyl vanillin and aqueous solvent.

Rock Salt: Crystallized sodium chloride.

Ice Cubes: Water- H2O

Main Chemicals, Compounds, Components

The two major components of my project will be the rock salt (NaCl) and Ice (H2O). When you add salt to water the salt dissolves into particles which are the ions of sodium chloride.The salt then lowers the freezing point of water preventing it from refreezing further.

Chemistry's Role

Rock Salt- used to melt ice. Contains NaCl. Naturally occurring; formed next to large bodies of water.

Ice(Water)- H2O Naturally Occurring. Essential for life.

Sugar-C6H12O6 + C6H12O6 => C12H22O11 + H2. Sugar is produced when glucose and fructose are combined by condensation. Throughout the process a water molecule is removed.

Vanilla- Comes from the natural plant Vanillin. Chemical Formula is C8H8O3

Milk- Milk does not necessarily have a chemical formula. It is a colloid of butter-fat molecules with fluid that is water based. There are too many components in milk for it to have a chemical formula.

Background Research

The project is not necessarily focusing on ice cream instead, how rock salt is used. Rock salt is commonly used for melting ice on roads and sidewalks. Not many people know that it can also be used for making ice cream. The rock salt forces the ice to melt. When the liquid in the smaller bag absorbs heat, the temperature in the mix lowers until it begins to freeze.If salt was not added, the ice would melt slowly. Then the mixture would stop at the temperature of melting ice. However, when the salt is added, the ice will melt faster. Since the larger bag loses large amounts of heat, the mixture will eventually reach the freezing temperature of melting saltwater ice.

Rock salt forms all over the world. It can be found in large bodies of water areas which have evaporated. Salt is essential for life, an average human contains about 250g of it in their body. Fortunatley, we have large oceans where salt can be found.

Rock salt was first found when miners were searching for coal. Afterward salt became very popular and was mined often. It is still mined today. These mines contain pathways with salt that has already been extracted.Large chunks of salt are carried out to be crushed into smaller portions. Before the salt is stored, anti- caking agent is added to prevent the salt from clotting.

Then salt is distributed to stores for our safety in the cold weather or for a simple pleasurement of homemade ice cream.

Resources

Sugar information: http://education.jlab.org/qa/sugar_01.html

Milk information: http://www.ilri.org/InfoServ/Webpub/fulldocs/ilca_manual4/Milkchemistry.htm

Vanilla information:http://en.wikipedia.org/wiki/Vanillin

Rock Salt information: http://www.onlinerocksalt.co.uk/what-is-rock-salt.html, http://www.makeicecream.com/howdoesrocsa.html,

http://www.stevespanglerscience.com/experiment/how-does-salt-melt-ice

About the Author

My name is Valerie Johnson and I am a student at Senior High School. I enjoy reading, dancing, cheerleading, and the studying the Roman Catholic Church. I have made ice cream with rock salt for about two years now and just began to understand why rock salt worked better than kitchen salt. My absolute favorite flavor of ice cream is cookie dough which unfortunately is hard to make this way.