Question

The number of molecules per unit volume (n) of a gas is given by

• A. $\frac{P}{kT}$
• B. $\frac{kT}{P}$
• C. $\frac{P}{RT}$
• D. $\frac{RT}{P}$

Answer 1

Answer: (D)

$P\forall =nRT$
$n=\frac{P}{RT}$
$\Rightarrow$ no of molecule $=n\cdot N_A$
$=\frac{P}{RT}\cdot N_A$
$\frac{P}{R/N_A}$
$\Rightarrow \frac{p}{KT}$= no.of mol