Lowering of vapour pressure is highest for

$60 \ g$ of Urea (Mol. wt $60$) was dissolved in $9.9 \ moles$ of water. If the vapour pressure of pure water is $P_o$,the vapour pressure of the solution is: (in $P_o$)

In a solution,the mole ratio of pentane $(A)$ and hexane $(B)$ is $1:4$. At $20^o C$,the vapor pressures of these pure hydrocarbons are $440 \ mm$ and $120 \ mm$ respectively. The mole fraction of pentane in the vapor phase is.....

$1 \ mol$ each of the following solutes are taken in $5 \ mol$ of water:
$(i) \ NaCl$
$(ii) \ K_2SO_4$
$(iii) \ Na_3PO_4$
$(iv) \ \text{glucose}$
Assuming $100 \%$ ionization of the electrolytes,the relative decrease in vapor pressure will be in the order:

$A$ gaseous mixture of two substances $A$ and $B$,under a total pressure of $0.8 \ atm$ is in equilibrium with an ideal liquid solution. The mole fraction of substance $A$ is $0.5$ in the vapour phase and $0.2$ in the liquid phase. The vapour pressure of pure liquid $A$ is $...... \ atm$. (Nearest integer)

The vapour pressure of pure benzene and toluene are $160$ $mm \ Hg$ and $60$ $mm \ Hg$ respectively. The mole fraction of benzene in the vapour phase in contact with an equimolar solution of benzene and toluene is: