Amount of oxygen required for combustion of $1 \, kg$ of a mixture of butane and isobutane is ............. $kg$.

At the same temperature and pressure,if the mass of $3 \ L$ of a hydrocarbon is equal to the mass of $3 \ L$ of $CO_2$,what is the molecular formula of the hydrocarbon?

$20 \ mL$ of methane is completely burnt using $50 \ mL$ of oxygen. The volume of the gas left after cooling to room temperature is (in $mL$)

The hardness of a water sample containing $10^{-3} \; M \; MgSO_{4}$ expressed as $CaCO_{3}$ equivalents (in $ppm$) is (molar mass of $MgSO_{4}$ is $120.37 \; g/mol$)

Consider the complete combustion of butane. The amount of butane utilized to produce $72.0 \ g$ of water is $.... \times 10^{-1} \ g$ (in nearest integer).

$100 \, mL$ of $0.1 \, N \, HCl$ is neutralized by $0.2 \, N \, NaOH$ solution. After adding $30 \, mL$ of $NaOH$ solution,the neutralization is continued using $0.25 \, N \, KOH$. Calculate the volume of $KOH$ in $mL$ required to complete the neutralization.