How many grams of $NaCl$ are decomposed by $4.9 \ g$ of $H_2SO_4$ to produce sodium hydrogen sulfate and $1.825 \ g$ of $HCl$? $[Na = 23, Cl = 35.5, S = 32, H = 1, O = 16]$

$A$ 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 $35.5 \ u$)

What mass of $95 \%$ pure $CaCO_3$ will be required to neutralise $50 \ mL$ of $0.5 \ M \ HCl$ solution according to the following reaction? (In $g$)
$CaCO_{3(s)} + 2HCl_{(aq)} \rightarrow CaCl_{2(aq)} + CO_{2(g)} + H_2O_{(l)}$
[Calculate up to the second decimal place]

In dilute aqueous $H_2SO_4$,the complex diaquodioxalatoferrate$(II)$ is oxidized by $MnO_4^-$. For this reaction,the ratio of the rate of change of $[H^{+}]$ to the rate of change of $[MnO_4^-]$ is

How much solid oxalic acid (Molecular weight $126$) has to be weighed to prepare $100 \ mL$ of exactly $0.1 \ N$ oxalic acid solution in water (in $g$)?

$C_2H_4$ can react with $H_2$ in the presence of a catalyst to form $C_2H_6$ as per the following reaction: $C_2H_{4(g)} + H_{2(g)} \xrightarrow{\text{Catalyst}} C_2H_{6(g)}$. The amount of $C_2H_4$ in grams required to produce $50 \ g$ of $C_2H_6$ is: (in $g$)