Question

At constant pressure, density of a gas is :

• A. directly proportional to absolute temperature
• B. inversely proportional to absolute temperature
• C. independent of temperature
• D. directly proportional to square root of absolute temperature

Answer 1

Answer: (B)

$Density=\frac{mass\left(w\right)}{Volume\left(V\right)}$
Now by ideal gas equation, PV = nRT
So this gives $PV=\frac{w}{M}RT$, where M is the molecular weight
So on putting the value of w, we get
Density, $d=\frac{PM}{RT}$
Clearly if pressure is constant, density is inversely proportional to temperature (T)