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

When ${CO_2}_{(g)}$ is passed over hot coke,it is reduced to ${CO}_{(g)}$. When $0.5 \, L$ of ${CO_2}_{(g)}$ is passed over hot coke,the total volume of the gas increases by $700 \, mL$ at $STP$. The composition of the resulting gaseous mixture is:

$A$ mixture of $2.3 \ g$ formic acid and $4.5 \ g$ oxalic acid is treated with conc. $H_2SO_4$. The evolved gaseous mixture is passed through $KOH$ pellets. Weight of the remaining product at $STP$ is .......... $g$.

The hydrated salt $Na_2SO_4 \cdot nH_2O$ undergoes $55.9 \%$ loss in weight on heating and becomes anhydrous. The value of $n$ will be?

$0.092 \ g$ of a compound with the molecular formula $C_3H_8O_3$ on reaction with an excess of $CH_3MgI$ gives $67.00 \ mL$ of methane at $STP$. The number of active hydrogen atoms present in a molecule of the compound is

If $20 \ mL$ of $0.4 \ N \ NaOH$ solution completely neutralises $40 \ mL$ of a dibasic acid,the molarity of the acid solution is $.......... \ M$.