1 mL of " $x$ volume" $\mathrm{H}_2 \mathrm{O}_2$ solution on heating gives 20 mL of oxygen gas at STP. The $(w / v) \%$ corresponding to " $x$ volume" of $\mathrm{H}_2 \mathrm{O}_2$ is

In a mixture of liquids $A$ and $B$, if the mole fractions of component $A$ in vapour phase and liquid mixture are $x_1$ and $x_2$ respectively, then the total vapour pressure of liquid mixture is

(Where $p_{\mathrm{A}}^0$ and $p_{\mathrm{B}}^0$ are the vapour pressure of pure $A$ and $B$ )

Two liquids ' $A$ ' and ' $B$ ' form an ideal solution. At 300 K , the vapour pressure of a solution containing 1 mole of ' $A$ ' and 3 moles of ' $B$ ' is 550 mm Hg . At the same temperature, if one more mole of ' $B$ ' is added to the solution, the vapour pressure of solution increases to 560 mm Hg . Then the ratio of vapour pressures of $A$ and $B$ in their pure state is

Which one of the following mixtures can be separated by steam distillation technique?