Given $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O : \Delta H = -72 \ \text{kcal}$,calculate the energy required for the formation of $1.6 \ \text{g}$ of glucose.

Haemoglobin contains $0.33\%$ of iron by weight. The molecular weight of haemoglobin is approximately $67200$. The number of iron atoms (At. wt. of $Fe = 56$) present in one molecule of haemoglobin is

$30.0 \ mL$ of the given $HCl$ solution requires $20.0 \ mL$ of $0.1 \ M$ sodium carbonate solution for complete neutralisation. What is the volume of this $HCl$ solution required to neutralise $30.0 \ mL$ of $0.2 \ M$ $NaOH$ solution (in $mL$)?

$A$ sample of a metal oxide has the formula $M_{0.83}O_{1.00}$. The metal $M$ can exist in two oxidation states,$+2$ and $+3$. In the sample of $M_{0.83}O_{1.00}$,the percentage of metal ions existing in the $+2$ oxidation state is $.........\%$ (nearest integer).

$A$ solution $(5 \, mL)$ of an acid $X$ is completely neutralized by $y \, mL$ of $1 \, M \, NaOH$. The same volume $(y \, mL)$ of $1 \, M \, NaOH$ is required to neutralize $10 \, mL$ of $0.6 \, M \, H_2SO_4$ completely. The normality $(N)$ of the acid $X$ is $......$

The mass percentage composition of dry air at sea level is approximately $N_2: 63 \%$,$O_2: 16 \%$,$Kr: 21 \%$. If the total pressure is $p \ atm$,calculate the partial pressure of each component respectively. (Molecular weights: $N_2 = 28, O_2 = 32, Kr = 84$)