What volume of Hydrogen gas,at $273 \ K$ and $1 \ atm$ pressure,will be consumed in obtaining $21.6 \ g$ of elemental boron (atomic mass $= 10.8$) from the reduction of boron trichloride by Hydrogen? (Answer in $L$)

$10 \ mL$ of an aqueous solution containing $222 \ mg$ of calcium chloride $(mol. wt. = 111)$ is diluted to $100 \ mL$. The concentration of chloride ion in the resulting solution is $..... \ mol/L$.

The weight of oxalic acid required to neutralize $100 \, cc$ of a normal solution of $NaOH$ is ........ $gm$.

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 $g$)?

How many grams of zinc are required to produce $224 \ mL$ of hydrogen from dilute $H_2SO_4$ at $STP$?

Dissolving $1.24 \ g$ of white phosphorus in boiling $NaOH$ solution in an inert atmosphere gives a gas $Q$. The amount of $CuSO_4$ (in $g$) required to completely consume the gas $Q$ is. . . . [Given: Atomic mass of $H = 1, O = 16, Na = 23, P = 31, S = 32, Cu = 63$]