How many $g$ of $H_2SO_4$ are present in $0.25 \, \text{mol}$ of $H_2SO_4$?

Assertion : Equal moles of different substances contain same number of constituent particles.
Reason : Equal weights of different substances contain the same number of constituent particles.

Which of the following has the largest number of atoms?

The number of hydrogen atoms present in $5.4 \ g$ of urea is : (Given : Molar mass of urea: $60 \ g \ mol^{-1}$, $N_{A} = 6.022 \times 10^{23} \ particles \ mol^{-1}$)

How many $CaF_2$ formula units are present in $146.4 \ g$ of $CaF_2$? (Molar mass of $CaF_2 = 78.08 \ g/mol$)

Choose the correct option for the mole fraction of both components in a gaseous mixture containing $7 \ g$ of nitrogen and $8 \ g$ of oxygen.