When $30 \ mL$ of $H_2$ reacts with $20 \ mL$ of $O_2$ to form water,what is leftover when the reaction ends?

In Ostwald's process for the manufacture of nitric acid,the first step involves the oxidation of ammonia gas by oxygen gas to give nitric oxide gas and steam. What is the maximum weight of nitric oxide that can be obtained starting only with $10.00 \, g$ of ammonia and $20.00 \, g$ of oxygen?

Assume carbon burns according to the following equation:
$2C_{(s)} + O_{2(g)} \rightarrow 2CO_{(g)}$
When $12 \ g$ of carbon is burnt in $48 \ g$ of oxygen,the volume of carbon monoxide produced is $...... \times 10^{-1} \ L$ at $STP$ [nearest integer].
[Given: Assume $CO$ as an ideal gas,molar mass of $C = 12 \ g \ mol^{-1}$,molar mass of $O = 16 \ g \ mol^{-1}$,and molar volume of an ideal gas at $STP$ = $22.7 \ L \ mol^{-1}$]

In the following reactions,identify $P, Q$ and $R$,respectively:
$I. 3Fe_2O_3 + CO \longrightarrow 2P + CO_2 \uparrow$
$II. Fe_3O_4 + 4CO \longrightarrow 3Q + 4CO_2 \uparrow$
$III. Fe_2O_3 + CO \longrightarrow 2R + CO_2 \uparrow$

How many moles of lead $(II)$ chloride will be formed from a reaction between $6.5 \ g$ of $PbO$ and $3.2 \ g$ of $HCl$?

In a $1 \ L$ vessel, $10 \ \text{moles}$ of methane and $50 \ \text{moles}$ of $O_2$ are present. The number of moles of $O_2$, water, and $CO_2$ present in the vessel after the vessel is heated to burn methane completely are respectively: