Phosphine $[PH_{3(g)}]$ decomposes to produce vapours of phosphorus $(P_4)$ and $H_2$ gas. What will be the change in volume when $100 \ mL$ of phosphine is decomposed?

When $1 \ L$ of $CO_2$ is heated with graphite,the volume of the gases collected is $1.8 \ L$. What will be the number of moles of $CO$ produced at $STP$?

Excess of $NaOH\, (aq)$ was added to $100\, mL$ of $FeCl_3\, (aq)$ resulting in $2.14\, g$ of $Fe(OH)_3$. The molarity of $FeCl_3\, (aq)$ is (Given molar mass of $Fe=56\, g\, mol^{-1}$ and molar mass of $Cl=35.5\, g\, mol^{-1}$) (in $, M$)

$5 \, N$ $H_2SO_4$ was diluted from $1 \, L$ to $10 \, L$. The normality of the solution obtained is.....$N$.

If the density of $1 \ mol$ of a gas at $NTP$ is $0.1784 \ g/L$,what is the weight of $1 \ mol$ of the gas in $g$?

$A$ metal chloride contains $55.0 \%$ of chlorine by weight. $100 \ mL$ of vapours of the metal chloride at $STP$ weigh $0.57 \ g$. The molecular formula of the metal chloride is $...$. (Given: Atomic mass of chlorine is $35.5 \ u$)