The number of moles of $Br_2$ produced when two moles of potassium permanganate are treated with excess potassium bromide in aqueous acid medium is

The drain cleaner,Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at $20^{\circ} C$ and $1 \, bar$ will be released when $0.15 \, g$ of aluminum reacts?

The volume of oxygen required for complete combustion of $0.25 \ mol$ of methane at $S.T.P.$ is (in $dm^{3}$)

When a $1.0 \, g$ mixture of $NaHCO_3$ and $Na_2CO_3$ is heated at $150^{\circ}C$,$112.0 \, mL$ of $CO_2$ is produced at $STP$. Calculate the percentage of $Na_2CO_3$ in the mixture. $(Na = 23, C = 12, O = 16)$

How much solid oxalic acid (Molecular weight $126$) has to be weighed to prepare $100 \ mL$ of exactly $0.1 \ N$ oxalic acid solution in water (in $g$)?

Calculate the concentration of nitric acid in moles per litre in a sample which has a density of $1.41 \, g \, mL^{-1}$ and the mass percent of nitric acid in it is $69 \%$.