$100 \ mL$ of $PH_3$ when completely decomposed produces phosphorus and hydrogen. The change in volume of the gas is
$PH_{3(g)} \longrightarrow P_{(s)} + \frac{3}{2} H_{2(g)}$

Which of the following reactions exhibits good atom economy according to the principles of green chemistry?

What ratio by mass of $Ne$ and $CH_4$ should be mixed so that the partial pressure exerted by each gas is the same?

The molarity of a solution made by mixing $50 \ mL$ of conc. $H_2SO_4$ $(36 \ N)$ with $50 \ mL$ of water is ...... $M$.

How many grams of $Cu(NO_3)_2$ are needed to obtain $1 \ g$ of copper? $($ Atomic mass: $Cu = 63.5, N = 14, O = 16$ $)$

Calculate the approximate mass (in $g$) of $H_2S$ required for the following reaction when $15 \ L$ of oxygen at $STP$ reacts completely.
$2 H_2S_{(g)} + 3 O_{2(g)} \longrightarrow 2 SO_{2(g)} + 2 H_2O_{(g)}$
(molar mass of $H_2S = 34 \ g \ mol^{-1}$)