$138 \ g$ of ethyl alcohol is mixed with $72 \ g$ of water. The ratio of mole fraction of alcohol to water is

Calculate the number of moles in $11.2 \ L$ of oxygen gas at $STP$.

The number of atoms present in $0.1 \ mol$ of a triatomic gas is: $(N_A = 6.022 \times 10^{23} \ mol^{-1})$

The number of moles and volume in $56 \ g$ of nitrogen $(N_2)$ are respectively:

The mass of $112 \ cm^3$ of $NH_3$ gas at $STP$ is (in $g$)

The number of $N$ atoms in $681 \ g$ of $C_{7}H_{5}N_{3}O_{6}$ is $x \times 10^{21}$. The value of $x$ is $.....$ $(N_{A} = 6.02 \times 10^{23} \ mol^{-1})$ (Nearest Integer)