The volume of water to be added to $100 \, cm^3$ of $0.5 \, N \, H_2SO_4$ to get decinormal concentration is ........ $cm^3$.

In the Victor Meyer method,$0.2 \ g$ of a volatile substance displaces $56 \ mL$ of air at $STP$. The molar mass of the substance is:

$A$ cylinder contains a mixture of $5 \ g$ of $N_2$ and $6 \ g$ of $Ar$ gases. If the total pressure of the mixture of the gases in the cylinder is $30 \ bar$,then the partial pressure of $N_2$ gas is (in $bar$)

$1 \ L$ of $N_2$ and $\frac{7}{8} \ L$ of $O_2$ gases are mixed at the same temperature and pressure. What is the relationship between their masses in the mixture?

Calcium carbonate reacts with aqueous $HCl$ to give $CaCl_{2}$ and $CO_{2}$ according to the reaction,
$CaCO_{3(s)} + 2HCl_{(aq)} \rightarrow CaCl_{2(aq)} + CO_{2(g)} + H_{2}O_{(l)}$
What mass of $CaCO_{3}$ is required to react completely with $25 \ mL$ of $0.75 \ M$ $HCl$ (in $g$)?

What is the value of percent atom economy if the formula weight of the product is $46 \ u$ and the sum of the formula weight of all reactants is $92 \ u$ (in $\%$)?