Which state of matter has a definite volume but no definite shape?

Provide the mathematical expression for Dalton's law of partial pressure.

The densities of hydrogen and oxygen are $0.09 \ g \ L^{-1}$ and $1.44 \ g \ L^{-1}$ respectively. If the rate of diffusion of hydrogen is $1$,then the rate of diffusion of oxygen in the same units will be:

$50 \ mL$ of hydrogen diffuses out through a small hole from a vessel in $20 \ min$. The time needed for $40 \ mL$ of oxygen to diffuse out is ............. $min$.

Which of the following gas mixtures will not obey Dalton's law of partial pressure?

If $X \, mL$ of $H_2$ gas diffuses through a hole in a container in $5 \, s$,what is the time taken for the diffusion of the same volume of another gas under identical conditions?