Quiz

Okay, I think I did the right quiz

1. Classify the following as either a chemical or physical change.
Burning wood - would be a chemical change, since it changes the chemical compounds
Crushing a rock - would be a physical change, because even in small pieces, it's still a rock
Dissolving sugar in water - my intuition was correct. I thought it was a physical change because mixing sugar and water gives you sugar water, not something new or different.
The rusting of iron - is a chemical change. The interaction between iron and water or whatever gives you a whole new thing, rust!

2. Classify the following as to whether or not they are pure substances or mixtures.
milk is a mixture of several things, water, fat, and sugars mostly
table salt I thought was pure, but table salt is mostly iodized and has anti caking agents
sugar I figured pure
steel I thought pure, and the answer said a homogeneous mixture of iron and carbon. I guess because it is a mixture that cannot be separated.

3. A cup of black coffee is considered to be __?__ and a/an __?__ substance.
(b) homogeneous…..impure I guessed homogeneous and impure because is is a mixture of coffee and water that cannot be separated

4. The boiling of water is considered to be a __?__ change and the temperature at which water boils is considered to be a __?__ property.
(d) physical…..physical The change of boiling water is a physical change since chemically, it hasn't changed. The temp at which water boils is a physical property, since it is not a chemical.