Making hydrogen gas at home #shorts

The hydrogen gas is

In which of the following conditions, the distance between the molecules of hydrogen gas would increase ? (i) Increasing pressure on hydrogen contained in a closed container. (ii) Some hydrogen gas leaking out of the container. (iii) Increasing the volume of the container of hydrogen gas . (iv) Adding more hydrogen gas to the container without increasing the volume of the container.

In which of the following reaction hydrogen gas will not be evolved?

The ratio of the velocity of sound in hydrogen gas to that in helium gas at the same temperature is

Hydrogen gas is not evolved by:

Hydrogen gas is ____ to litmus.