$2 \ N - HCl$ will have the same molar concentration as $....... \ N - H_2SO_4$

$15 \ mL$ of $N/10$ $NaOH$ solution completely neutralizes $12 \ mL$ of $H_2SO_4$ solution. The normality of $H_2SO_4$ solution will be:

$10 \ mL$ of a gaseous hydrocarbon on combustion gives $40 \ mL$ of $CO_{2(g)}$ and $50 \ mL$ of water vapour. The total number of carbon and hydrogen atoms in the hydrocarbon is:

The molarity of a $0.2 \ N \ Na_2CO_3$ solution is ........ $M$.

How much heat change in $kJ$ will occur when $233.0 \, g$ of calcium oxide reacts with sufficient carbon to produce $CaC_2$? The reaction is: $CaO_{(s)} + 3C_{(s)} \to CaC_{2(s)} + CO_{(g)}$; $\Delta H^o = 464.8 \, kJ/mol$.

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