The hardness of a water sample (in terms of equivalents of $CaCO_3$) containing $10^{-3} \ M \ CaSO_4$ is ................... $ppm$ (Molecular mass of $CaSO_4 = 136 \ g \ mol^{-1}$)

What will be the normality of the salt solution obtained by neutralising $x \ mL$ $y \ (N)$ $HCl$ with $y \ mL$ $x \ (N)$ $NaOH$, and finally adding $(x+y) \ mL$ distilled water?

What volume of $10 \, M \, HCl$ is required to prepare $2.00 \, L$ of $5 \, M \, HCl$ by dilution with water (in $, L$)?

$A$ cylinder of cooking gas in a household contains $11.6 \, kg$ of butane. The thermochemical reaction for the combustion of butane is,
$2 C_4H_{10(g)} + 13 O_{2(g)} \longrightarrow 8 CO_{2(g)} + 10 H_2O_{(l)}$
$\Delta H = -2658 \, kJ/mol$
If the household needs $15000 \, kJ$ of energy per day,the cooking gas cylinder will last for about $...... \, days$.

What is obtained when one mole of calcium phosphide is reacted with excess water?

$5\, g$ of benzene on nitration gave $6.6\, g$ of nitrobenzene. The theoretical yield of the nitrobenzene will be $..............$ $g$.