The ratio of amounts of $H_2S$ needed to precipitate all the metal ions from $100 \ mL$ of $1 \ M$ $AgNO_3$ and $100 \ mL$ of $1 \ M$ $CuSO_4$ will be

If isobutane and $n$-butane are present in a gas,then how much oxygen should be required for complete combustion of $10 \ kg$ of this gas? (in $kg$)

The volume (in $mL$) of $0.1\, N$ $NaOH$ required to neutralize $10\, mL$ of $0.1\, N$ phosphinic acid is........

$A$ solution of $H_2SO_4$ is $31.4 \%$ $H_2SO_4$ by mass and has a density of $1.25 \ g \ mL^{-1}$. The molarity of the $H_2SO_4$ solution is . . . . . . $M$ (nearest integer) [Given molar mass of $H_2SO_4 = 98 \ g \ mol^{-1}$]

$417 \ g$ of $PCl_{5(s)}$ is kept in an open container where it reacts with moisture from air to form $POCl_{3(s)}$ and $HCl_{(g)}$. $A$ few hours later,the solid left in the container weighed only $395 \ g$. The percentage of $PCl_5$ converted to $POCl_3$ is: .............. $\%$ $(P = 31, Cl = 35.5, O = 16, H = 1)$

$A$ gaseous mixture contains $CH_4$ and $C_2H_6$ in equimolecular proportion. The weight of $2.24 \ L$ of this mixture at $NTP$ is .............. $g$.