Mass of $NaOH$ required for formation of $100 \ mL$ of its decimolar solution is .............. $g$.

How many grams of $KClO_3$ must be decomposed to obtain $2.40 \, L$ of $O_2$ gas at $25 \, ^\circ C$ and $740 \, mm \, Hg$ pressure (in $, g$)? (Molar mass of $KClO_3 = 122.5 \, g \, mol^{-1}$)

The mass of iron converted into $Fe_3O_4$ by the action of $18\text{ g}$ of steam is : (Given: Molar mass of $H$,$O$ and Fe are $1$,$16$ and $56\text{ g mol}^{-1}$ respectively). Assume iron is present in excess: (in $\text{ g}$)

Combustion of $10 \ mL$ of a gaseous hydrocarbon gives $40 \ mL$ of $CO_2$ and $50 \ mL$ of water vapour under the same conditions. The molecular formula of the hydrocarbon is

The number of molecules in $100 \, mL$ of $0.02 \, N$ $H_2SO_4$ is .....

Calculate the volume of $O_2$ at $STP$ required for the combustion of $1 \, \text{mol}$ of carbon disulfide $(CS_2)$ in $L$.