The volumes of two $HCl$ solutions $A$ (Normality $= 0.5 \ N$) and $B$ (Normality $= 0.1 \ N$) to be mixed for preparing $2 \ L$ of $0.2 \ N \ HCl$ are:

Suppose a cooking gas cylinder contains $11.2 \, kg$ of isobutane. The thermochemical equation for the combustion of butane is given below:
$C_4H_{10}(g) + \frac{13}{2} O_2(g) \to 4CO_2(g) + 5H_2O(\ell); \Delta H = -2658 \, kJ$
If a family requires $15000 \, kJ$ of energy per day for cooking,how many days will the cylinder last?

Volume of $3 \ M \ NaOH$ (formula weight $40 \ g \ mol^{-1}$) which can be prepared from $84 \ g$ of $NaOH$ is $ . . . . . . \times 10^{-1} \ dm^3$.

The volume of $0.1 \ M$ oxalic acid that can be completely oxidized by $20 \ mL$ of $0.025 \ M$ $KMnO_4$ solution is (in $mL$)

One and a half mole of oxygen combine with aluminium to form $Al_2O_3$. The weight of aluminium metal used in this reaction is .............. $g$ (Atomic weight of $Al = 27$).

Given the ratio of masses of nitrogen and oxygen in a particular gaseous mixture is $4: 1$. Calculate the ratio of the number of their molecules.