$A$ mixture of $H_2$ and $O_2$ at $1 \, atm$ pressure contains $20 \%$ by weight of $H_2$. Find out the partial pressure of $H_2$ in $atm$.

If a $100 \ mL$ solution contains $X \ g$ of $Na_2CO_3$ and its concentration is $Y \ M$,then $X$ and $Y$ are respectively ...............

$0.01$ mole of iodoform $(CHI_3)$ reacts with $Ag$ to produce a gas whose volume at $NTP$ is ............. $mL$.
$2CHI_3 + 6Ag \to 6AgI_{(s)} + C_2H_{2(g)}$

$40\%$ of a mixture of $0.2 \ mol$ of $N_2$ and $0.6 \ mol$ of $H_2$ reacts to give $NH_3$ according to the equation:
$N_{2(g)} + 3H_{2(g)} \rightleftharpoons 2NH_{3(g)}$
at constant temperature and pressure. What is the ratio of the final volume to the initial volume of gases?

The number of moles of hydrogen molecules required to produce $20$ moles of ammonia through Haber's process is

$100 \, mL$ of a mixture of $NaOH$ and $Na_2SO_4$ is neutralized by $10 \, mL$ of $0.5 \, M$ $H_2SO_4$. Hence,the mass of $NaOH$ in $100 \, mL$ solution is ........... $g$.