Question

practice problems
in your notebook, solve the following problems.
section 2.1 matter

1. which of the following is not a physical change?

a. dissolving sugar in water c. evaporating sea water to obtain salt
b. burning gasoline in an engine d. slicing a piece of bread

1. which of the following is not a property of a gas?

a. has a definite shape c. assumes the shape of its container
b. has no definite volume d. easily compressible

1. which of the following is not a physical property of sucrose?

a. solid at room temperature c. dissolves in water
b. decomposes when heated d. tastes sweet

1. which of the following is typically in a different physical state than the other three at room temperature?

a. salt b. sugar c. flour d. water

Explanation:

Question 1

A physical change doesn't alter the substance's chemical identity. Dissolving sugar (a), evaporating sea water (c), and slicing bread (d) are physical changes as they don't form new substances. Burning gasoline (b) involves combustion, forming new substances (like CO₂, H₂O), so it's a chemical change, not physical.

Gases have no definite shape (they take the container's shape), no definite volume, and are easily compressible. A definite shape is a property of solids, not gases. So option a is not a gas property.

Physical properties can be observed without changing the substance's chemical structure. Being solid (a), dissolving in water (c), and tasting sweet (d) are physical. Decomposing when heated (b) involves a chemical reaction (breaking down into new substances), so it's a chemical property, not physical.

Answer:

b. burning gasoline in an engine

Question 2