$C_2H_4$ 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 $g$)

What is produced when $1 \ mol$ of calcium phosphide reacts with excess water?
$(Hint: Ca_3P_2 + H_2O (excess) \rightarrow Ca(OH)_2 + 2PH_3)$

The volumes of two $HCl$ solutions $A$ (Normality $= 0.5 \ N$) and $B$ (Normality $= 0.1 \ N$) to be mixed for preparing $2 \ L$ of $0.2 \ N \ HCl$ are:

Zinc reacts with hydrochloric acid to give hydrogen and zinc chloride. The volume of hydrogen gas produced at $STP$ from the reaction of $11.5 \ g$ of zinc with excess $HCl$ is $.......... \ L$ (Nearest integer) (Given: Molar mass of $Zn$ is $65.4 \ g \ mol^{-1}$ and Molar volume of $H_2$ at $STP = 22.7 \ L$)

To neutralize $25 \, mL$ of $0.25 \, M$ $Na_2CO_3$ solution,how much volume of $0.5 \, M$ $HCl$ is required? (Note: The reaction is $Na_2CO_3 + 2HCl \rightarrow 2NaCl + H_2O + CO_2$)

$12 \ g$ of $Mg$ (atomic mass $24$) on reacting completely with acid gives hydrogen gas,the volume of which at $STP$ would be ............... $L$.