Question

Density of a gaseous oxide is $0.0013g/cc$ at NTP. It's vapour density is________________.

• A. $0.0013$
• B. $14.48$
• C. $29.12$
• D. Data insufficient.

Answer 1

Answer: (B)

$14.48$

The vapour density when the density of air is $0.001293g/ml$ is $14.48gm.$

Explanation:

We know that: Molecular Mass$=2\times VapourDensity$

At STP or under standard conditions of pressure and temperature, $22.4l$ of any gas equals to $1$ mole.

That is, 1 mole $=22.4l$

The density of air is given as $0.001293g/ml$

The volume of gas$=22400ml$

We know that mass$=density\times volume$

Therefore, rearranging the above equation, $Mass=0.001293\times 22400=28.96g$

Also we know that, Molecular Mass$=2\times VapourDensity$

Rearranging the equation we get,

$VapourDensity=\frac{MolecularMass}{2}$

$=\frac{28.96}{2}$

$=14.48gm$