$A$ gas $A$ diffuses at a rate which is twice that of another gas $B$. The ratio of molecular weights of $A$ to $B$ is

Two statements are given below.
Statement-$I$: The ratio of the molar volume of a gas to that of an ideal gas at constant temperature and pressure is called the compressibility factor.
Statement-$II$: The $RMS$ velocity of a gas is directly proportional to the square root of $T(K)$.
The correct answer is

$A$ tube of length $1 \, m$ has identical pinholes at both ends. Ammonia gas at $1 \, atm$ pressure is introduced from one end,and $HCl$ gas at $P \, atm$ pressure is introduced from the other end at room temperature. If $NH_4Cl$ is formed at a distance of $60 \, cm$ from the end where $HCl$ was introduced,calculate the value of pressure $P$. (in $, atm$)

At $STP$,$0.50 \ mol$ $H_2$ gas and $1.0 \ mol$ $He$ gas:

Why does a sharp glass edge become smooth on heating it up to its melting point in a flame? Explain which property of liquids is responsible for this phenomenon.

What is the temperature at which the kinetic energy of $0.3 \text{ moles}$ of helium is equal to the kinetic energy of $0.4 \text{ moles}$ of argon at $400 \text{ K}$ (in $\text{ K}$)?