The set of numerical coefficients that balances the equation $K_2CrO_4 + HCl \to K_2Cr_2O_7 + KCl + H_2O$ is

$100 \ mL$ of $0.05 \ M$ $Cu^{2+}$ aqueous solution is added to $1 \ L$ of $0.1 \ M$ $KI$ solution. The number of moles of $I_2$ and $Cu_2I_2$ formed are respectively:

An electric discharge is passed through a mixture containing $50 \, c.c.$ of $O_2$ and $50 \, c.c.$ of $H_2$. The volume of the gases formed $(i)$ at room temperature and $(ii)$ at $110 \, ^oC$ will be

$1 \ g$ of sodium hydroxide was treated with $25 \ mL$ of $0.75 \ M \ HCl$ solution. The mass of sodium hydroxide left unreacted is equal to:

Calculate the number of moles of oxygen required to react with $6.8 \, g$ of ammonia in the following reaction:
$NH_3 + O_2 \to NO + H_2O$

The mass of $N_2F_4$ produced by the reaction of $2.0 \ mol$ of $NH_3$ and $8.0 \ mol$ of $F_2$ is $0.5 \ mol.$ What is the per cent yield?
$2NH_3 + 5F_2 \to N_2F_4 + 6HF$