Question

name:
ice cream in a bag
chemistry plays an important role in many everyday activities, including cooking and food preparation. when ingredients are mixed and energy is added or removed, physical and chemical changes can occur. one example we can look at is making ice cream, which forms when a liquid mixture freezes while being constantly mixed, which prevents large ice crystals from forming and creating a smooth texture.
in this lab, you will make ice cream using a plastic bag. ice and salt will be used to lower the freezing point of water, allowing the cream mixture to freeze more quickly. in ice, water molecules are arranged in an orderly pattern. when you add salt to the ice, the salt dissolves into ions, which interact with water molecules. when the ions interact with water molecules, they break up the pattern of water molecules on the microscopic level. on the macroscopic level, we see ice going through a phase change, melting into liquid water. as the ice melts, it absorbs heat, which allows the ice cream mixture to get colder and freeze into delicious ice cream!
essential vocabulary
find and highlight these words!
ion - atom with a charge
microscopic - very small; tiny
macroscopic - very large
phase change - when matter goes from one state to another as a result of an energy exchange
questions:

1. what is an ion?

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1. what is a phase change?

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1. what causes the ice cream mixture to go through a phase change?

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materials small ziploc bag, large ziploc bag, milk (or half and half), sugar, vanilla extract, ice, rock salt, measuring spoons, towel or gloves
procedure
part 1:
making the ice
cream mixture

1. add ½ cup of milk (or half-and-half) to the small ziploc
2. add 1 tablespoon of sugar to the small ziploc
3. add ¼ teaspoon of vanilla extract
4. seal the small ziploc tightly, letting no air escape

Explanation:

1. Defined using the provided vocabulary term for ion.
2. Defined using the provided vocabulary term for phase change.
3. Explained using the lab's description of salt, ice, and heat transfer.

Answer:

1. An ion is an atom with a charge.
2. A phase change is when matter goes from one state to another as a result of an energy exchange.
3. When salt is added to ice, the salt dissolves into ions that break up the ordered pattern of water molecules in ice, causing the ice to melt. As the ice melts, it absorbs heat from the ice cream mixture, lowering its temperature enough to freeze (a phase change from liquid to solid).