Question

An alternate way to state Avogadro’s law is "All other things being equal, the number of molecules in a gas is directly proportional to the volume of the gas." (a) What is the meaning of the term "directly proportional?" (b) What are the "other things" that must be equal?

a) (a) Number of molecules and volume change independently, (b) Pressure and temperature.
b) (a) Number of molecules and volume increase together, (b) Pressure and temperature.
c) (a) Number of molecules and volume decrease together, (b) Pressure and temperature.
d) (a) Number of molecules and volume are constant, (b) Pressure and temperature.

Answer 1

In Avogadro's Law, 'directly proportional' means that an increase in the number of molecules of a gas results in a proportional increase in volume, provided that the pressure and temperature remain constant.

Step-by-step explanation:

The term "directly proportional" means that two variables change together in the same proportion. In the context of Avogadro's law, it indicates that as the number of moles (or molecules) of a gas increases, the volume of the gas increases by an equivalent factor, assuming all other conditions remain constant.

The "other things" that must be equal to satisfy Avogadro's Law are pressure and temperature. This means that the pressure and temperature of the gas are held constant while observing the relationship between the number of molecules and volume.

Therefore, the correct answer to the student's question is (b): (a) Number of molecules and volume increase together, and (b) Pressure and temperature must be equal.