12) Homogeneous mixtures are also known as ________.
A) solids
B) compounds
C) elements
D) substances
E) solutions
13) The law of constant composition says ________.
A) that the composition of a compound is always the same
B) that all substances have the same composition
C) that the composition of an element is always the same
D) that the composition of a homogeneous mixture is always the same
E) that the composition of a heterogeneous mixture is always the same
14) Which of the following is an illustration of the law of constant composition?
A) Water boils at 100 °C at 1 atm pressure.
B) Water is 11% hydrogen and 89% oxygen by mass.
C) Water can be separated into other substances by a chemical process.
D) Water and salt have different boiling points.
E) Water is a compound.
15) In the following list, only ________ is not an example of a chemical reaction.
A) dissolution of a penny in nitric acid
B) the condensation of water vapor
C) a burning candle
D) the formation of polyethylene from ethylene
E) the rusting of iron