What is the volume (in litres) of oxygen at $STP$ required for complete combustion of $32 \,g$ of $CH_4$? (Molecular weight of $CH_4$ is $16$)

$A$ $1.85 \ g$ sample of an arsenic containing pesticide was chemically converted to $AsO_4^{3-}$ (atomic mass of $As = 74.9$) and titrated with $Pb^{2+}$ to form $Pb_3(AsO_4)_2$. If $20 \ mL$ of $0.1 \ M \ Pb^{2+}$ is required to reach the equivalence point,the mass percentage of arsenic in the pesticide sample is closest to

When a hydrocarbon $A$ undergoes combustion in the presence of air,it requires $9.5$ equivalents of oxygen and produces $3$ equivalents of water. What is the molecular formula of $A$?

$15 \ mL$ of $0.2 \ N$ alkali is required to complete neutralization of $30 \ mL$ acid solution. The concentration of the acid solution is ..... $N$.

At $NTP$,$40 \, mL$ of nitrogen reacts with hydrogen to form ammonia. According to the reaction $N_2 + 3H_2 \rightarrow 2NH_3$,the mass of ammonia formed will be ..... (in $, g$)

At $T \ K$, $100 \ L$ of dry oxygen is present in a sealed container. It is subjected to silent electric discharge, until the volumes of oxygen and ozone become equal. What is the volume (in litres) of ozone formed at $T \ K$?