$12 \ g$ of $Mg$ (atomic mass $24$) will react completely with acid to give:

Excess of carbon dioxide is passed through $50 \ mL$ of $0.5 \ M$ calcium hydroxide solution. After the completion of the reaction,the solution was evaporated to dryness. The solid calcium carbonate was completely neutralized with $0.1 \ N$ hydrochloric acid. The volume of hydrochloric acid required is (Atomic mass of calcium $= 40$ ) (in $cm^{3}$)

$100 \, mL$ of a given $H_2O_2$ sample in water (density $1.08 \, g/mL$) required $5 \, mL$ of $M/25 \, KMnO_4$ in acidic medium for its oxidation. Select the correct statement regarding $H_2O_2$ in the sample:

The complete combustion of one mole of benzene produces how many grams of carbon dioxide?

$A$ pre-weighed vessel is filled with $O_2$ and weighed at $STP$. It is then evacuated and filled with $SO_2$ gas at the same temperature and pressure,and weighed again. The weight of $O_2$ will be:

$100 \ mL$ of $0.1 \ N$ hypo solution is decolourised by the iodine liberated from the addition of $x \ g$ of crystalline copper sulphate to an excess of $KI$. The value of $x$ is ............. $g$ (molecular weight of $CuSO_4 \cdot 5H_2O$ is $250$).