The active mass of benzene $(C_6H_6 = 78)$ with a density of $1.56 \, g/mL$ is .......

Hardness of water is $200 \ ppm$. Calculate the molarity and normality of $CaCO_3$ in the water.

For the combustion reaction of $1 \ mol$ of benzene,if all reactants and products are in the gaseous state,then $\Delta n_{(g)}$ is equal to ......

The moles of methane required to produce $81 \ g$ of water after complete combustion is $.... \times 10^{-2} \ mol.$ [nearest integer]

According to the reaction,$Mg_{(s)} + 2HCl_{(aq)} \longrightarrow MgCl_{2_{(aq)}} + H_{2_{(g)}} \uparrow$,calculate the mass of $Mg$ required to liberate $4.48 \ dm^3$ of $H_2$ gas at $STP$. (Molar mass of $Mg = 24 \ g \ mol^{-1}$) (in $g$)

The number of chlorine atoms in $1.98 \ g$ of $BaCl_2$ is ..... (Atomic weight of $Ba = 137$,$Cl = 35.5$)