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