$A$ mixture of one mole each of $H_2$,$He$ and $O_2$ are enclosed in a cylinder of volume $V$ at temperature $T$. If the partial pressure of $H_2$ is $2 \ atm$,the total pressure of the gases in the cylinder is $....... \ atm$

State Dalton's Law of partial pressure,provide its mathematical formula,and explain aqueous tension.

$A$ gaseous mixture of $3$ gases $A$, $B$ and $C$ has a pressure of $10 \,atm$. The total number of moles is $10$. If the partial pressures of gases $A$ and $B$ are $3 \,atm$ and $1 \,atm$ respectively, and the molar mass of gas $C$ is $2 \,g/mol$, calculate the weight of $C$ in the mixture. (in $\,g$)

Which of the following relationships is correct,where $r$ is the rate of diffusion of a gas and $d$ is its density?

The rate of diffusion of a gas having a molar mass of $128 \ g/mol$ with respect to oxygen is ........... times.

Consider the following statements: For diatomic gases,the ratio $C_p/C_v$ is equal to:
$1$. $1.40$ (lower temperature)
$2$. $1.66$ (moderate temperature)
$3$. $1.29$ (higher temperature)
Which of the above statements are correct?