Volume of $0.5 \ mole$ of a gas at $1 \ atm$ pressure and $273 \ K$ is ............. $litres$.

In the equation $PV = nRT$,which of the following is $NOT$ equal to the value of $R$?

Air entering the lungs ends up in tiny sacs called alveoli. It is from the alveoli that oxygen diffuses into the blood. The average radius of the alveoli is $0.0050 \ cm$ and the air inside contains $14$ per cent oxygen. Assuming that the pressure in the alveoli is $1.0 \ atm$ and the temperature is $37 \ ^oC$,calculate the number of oxygen molecules in one of the alveoli.

At $27\, ^\circ C$ temperature and $1\, bar$ pressure,the volume of a gas is $25\, L$. If the temperature becomes $77\, ^\circ C$ at constant pressure,calculate the volume of the gas. (in $, L$)

For an ideal gas,the number of moles per litre in terms of its pressure $P$,gas constant $R$,and temperature $T$ is:

$4 \ g$ of an ideal gas occupies $5.6035 \ L$ of volume at $546 \ K$ and $2 \ atm$ pressure. What is its molecular weight?