Chapter 1
Chapter 2
Chapter 3
Labs
100

Where does a food scientist work and what do they do?

fields

labs

food

chemistry

100

Do all solids and liquids dissolve in water?

No. Sometimes there are sediments or layers.

100
What is attraction?

Molecules like each other, break off and combine with the new molecules.

100

What is Chromatography? What did we learn from our chromatography lab?

Chromatography is used to separate mixtures, specifically separate dye.

We used chromatography to determine if our dye was a pure substance, or if it was made from a mixture of colors. We learned that red dye was present (which could've been Red Dye #75).

200

Define molecule

A group of atoms

200

When we mixed water and salt together, the salt "disappeared". What is this called?


solubility or dissolving

200

Define emulsifier and give an example.

Something that allows liquids to mix, lecithin.

200

Why did the dye go up the paper in our Chromatography experiment?

The dye was attracted to the water molecules, which were attracted to the paper. The red dye got "stuck" to the paper and separate from the water molecules. The paper was able to filter the dye from the water and separate the mixture of colors.

300

Explain how mixtures and substances are different.

A mixture is a combination of substances where as a substance is a group of the same atoms or molecules

300

If I add 1 gram of salt to water, and 1 gram of sugar to water, will each new mixture have the same weight?

Yes, the weight of the matter doesn't change when it is mixed.

300

Why didn't oil and water/vinegar mix? How were we able to get them to mix?

They were not attracted to each other, we used an emulsifier, like lecithin, to get them to mix.

300

Even though the salt dissolved it was still in the water. How did we know that the salt was still there? (Think about what experiment we could create).

we can taste it

we can filter it out

we can let the water evaporate

400

If you had two white powders in front of you, how could you determine if they were the same or different?

- create a test where you put them in water and see if they dissolve

- smell them

- weigh them

400

If I combine water and hot chocolate powder, did I make a new substance?

Yes, the water and hot chocolate work together to make a new substance (hot chocolate)! We know this because it has new properties (color, smell, taste, texture).

400

What happened to the oil when we mixed lecithin in?

a. it evaporated

b. it became heavier

c. it broke into smaller particles (dissolved) and combined with the lecithin to connect to the water molecules

c. it broke into smaller particles (dissolved) and combined with the lecithin to connect to the water molecules

400

Why do scientists use models?

To show things too small or too big to see.

500

List 3 observable properties of substances and 3 observable properties of molecules.

Substances: color, smell, texture

Molecules: shape, size, weight, attraction to other molecules

500

What does it mean if molecules dissolve in a mixture?

They are attracted to each other so they break off from their own group of molecules and attach to the molecules from the other substance.

500

What is wrong with these two models?

1. Doesn't show attraction to other molecules

2. Doesn't show that lecithin is the molecule between oil and water/vinegar

500

Name the model we used to show properties of molecules...


Fan Model

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