Question

A colorless, odorless and tasteless gas, which is neutral to litmus paper and 14.4 times less dense than air is

Answer 1

Task:

A colorless, odorless and tasteless gas, which is neutral to litmus paper and 14.4 times less dense than air is

Solution:

The ratio of densities of two different gases is equal to the ratio of their molar weights.

$$\rho_ {1} / \rho_ {2} = \mathrm {M W} _ {1} / \mathrm {M W} _ {2}$$

The molar weight of air is 29 g/mol

$$\begin{array}{l} \rho_ {1} / \rho_ {2} = 14.4 = \mathrm {M W} _ {1} / \mathrm {M W} _ {2} \\ 29 / \mathrm{M W} _ {2} = 14.4 \\ \mathrm{M W} _ {2} = 29 / 14.4 = 2.01 \\ \end{array}$$

The only one gas has molar weight 2. It's H₂. And it is really colorless, odorless and tasteless gas, neutral to litmus paper

Answer: This gas is H₂