Question

what quantity is needed to convert between the moles of a given gaseous substance and its volume?
a avogadros number
b the molar volume
c the molar mass of the substance
d the density of the gas

Explanation:

To determine the quantity for converting moles of a gaseous substance to its volume, we analyze each option:

• Option a: Avogadro’s number relates moles to number of particles, not volume.
• Option b: Molar volume (e.g., \(22.4\space L/mol\) at STP) is the volume occupied by 1 mole of a gas. Using the formula \(Volume = Moles\times Molar\space Volume\), it directly converts between moles and volume.
• Option c: Molar mass converts moles to mass, not volume.
• Option d: Density (\(d=\frac{m}{V}\)) relates mass and volume, not moles and volume directly.

So the correct quantity is molar volume.

Answer:

b. the molar volume