At $S.T.P.$,$1 \ g$ $CaCO_3$ on decomposition gives $CO_2$ ............. $litres$.

How many millimoles of $H^{+}$ ions are present in $100 \, mL$ of $0.6 \, N \, H_3PO_4$?

$20 \ mL$ 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 molarity of $HNO_{3}$ in a sample which has density $1.4 \; g/mL$ and mass percentage of $63\%$ is . . . . . . $M$.
(Molecular Weight of $HNO_{3} = 63$)

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?

Formation of polyethylene from calcium carbide takes place as follows:
$CaC_2 + 2H_2O \to Ca(OH)_2 + C_2H_2$
$C_2H_2 + H_2 \to C_2H_4$
$n(C_2H_4) \to (-CH_2-CH_2-)_n$
The amount of polyethylene obtained from $64.1 \ kg$ of $CaC_2$ is......$kg$.