The number of moles of $H_2$ required to produce $10$ moles of $NH_3$ in the following reaction is:
$a H_{2(g)} + b NO_{2(g)} \longrightarrow c NH_{3(g)} + d H_2O_{(g)}$

One mole of nitrogen gas on reaction with $3.01 \times 10^{23}$ molecules of hydrogen gas produces

Calcium carbonate reacts with aqueous $HCl$ to give $CaCl_2$ and $CO_2$ according to the reaction given below: $CaCO_{3(s)} + 2HCl_{(aq)} \to CaCl_{2(aq)} + CO_{2(g)} + H_2O_{(l)}$
What mass of $CaCl_2$ will be formed when $250 \ mL$ of $0.76 \ M$ $HCl$ reacts with $1000 \ g$ of $CaCO_3$? Name the limiting reagent. Calculate the number of moles of $CaCl_2$ formed in the reaction.

$2 SO_{2(g)} + O_{2(g)} \rightarrow 2 SO_{3(g)}$
The above reaction is carried out in a vessel starting with partial pressures $P_{SO_{2}} = 250 \ mbar$,$P_{O_{2}} = 750 \ mbar$,and $P_{SO_{3}} = 0 \ mbar$. When the reaction is complete,the total pressure in the reaction vessel is $..... \ mbar$. (Round off to the nearest integer).

When $35 \ mL$ of $0.15 \ M$ lead nitrate solution is mixed with $20 \ mL$ of $0.12 \ M$ chromic sulphate solution,$....... \times 10^{-5}$ moles of lead sulphate precipitate out. (Round off to the Nearest Integer).

What are the combustion products of an aliphatic thiol $(RSH)$ at $298 \ K$?