If equal masses of methane $(CH_4)$ and hydrogen $(H_2)$ are mixed in an empty container at $25\,^oC$,what is the fraction of the total pressure exerted by hydrogen?

For preparing a $0.1 \ N$ solution of a compound from its impure sample,where the percentage purity is known,the weight of the substance required will be:

In $Fe_{0.96}O$,$Fe$ is present in $+2$ and $+3$ oxidation states. What is the mole fraction of $Fe^{2+}$ ions in the compound?

Calculate the mass of sodium acetate $(CH_{3}COONa)$ required to make $500 \,mL$ of $0.375 \,M$ aqueous solution. Molar mass of sodium acetate is $82.0245 \,g \,mol^{-1}$.

Upon mixing equal volumes of aqueous solutions of $0.1 \, M \, HCl$ and $0.2 \, M \, H_2SO_4$,the concentration of $H^{+}$ in the resulting solution is $.... \, mol / L$.

$10 \ mol$ of a mixture of hydrogen and oxygen gases at a pressure of $1 \ atm$ at constant volume and temperature,react to form $3.6 \ g$ of liquid water. The pressure of the resulting mixture will be closest to $..... \ atm$