Match the following gas laws with their respective equations.

Select one correct statement. In the gas equation,$PV = nRT$

Under which conditions will the density of a gas be maximum?

How many times the volume of a diatomic gas should be increased reversibly and adiabatically in order to reduce its $RMS$ velocity to half of its initial value?

$100 \, mL$ of $O_2$ and $H_2$ are kept at the same temperature and pressure. Which of the following is true regarding the number of molecules?

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.