Volume of $\frac{N}{10}$ $H_2SO_4$ required to neutralize $10 \ mL$ of $5 \ N$ $Na_2CO_3$ is.....$mL$.

$120 \ g$ of urea are present in $5 \ L$ of solution. The active mass of urea is:

$A$ 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 $atm$.

The weight of calcium oxide formed by burning $20 \ g$ of calcium in excess oxygen is $.... \ g$

Mass of $NaOH$ required for formation of $100 \ mL$ of its decimolar solution is .............. $g$.

How many grams of concentrated nitric acid solution should be used to prepare $250 \ mL$ of $2.0 \ M \ HNO_3$? The concentrated acid is $70\% \ HNO_3$ by mass.