$10 \, L$ solution of urea contains $240 \, g$ urea. The active mass of urea will be

$10 \ mL$ of a gaseous hydrocarbon on combustion gives $40 \ mL$ of $CO_{2(g)}$ and $50 \ mL$ of water vapour. The total number of carbon and hydrogen atoms in the hydrocarbon is:

$20 \, mL$ of a $1 \, N$ solution of $KMnO_4$ just reacts with $20 \, mL$ of a solution of oxalic acid. The weight of oxalic acid crystals in $1 \, L$ of the solution is $... \, g$

How many moles of ammonia are produced by $5$ moles of hydrogen (in $.3$)?

In the reaction,$2Al_{(s)} + 6HCl_{(aq)} \rightarrow 2Al^{3+}_{(aq)} + 6Cl^{-}_{(aq)} + 3H_{2(g)}$

When $500 \ mL$ of a gaseous hydrocarbon is burned in excess of $O_2$,it produces $2.5 \ L$ of $CO_2$ and $3.0 \ L$ of water vapor. What is the molecular formula of the hydrocarbon?