On adding a solute to a solvent having a vapour pressure of $0.80 \ atm$,the vapour pressure reduces to $0.60 \ atm$. The mole fraction of the solute is:

At $T \ K$, $0.1 \ mol$ of a non-volatile solute was dissolved in $0.9 \ mol$ of a volatile solvent. The vapour pressure of pure solvent is $0.9 \ bar$. What is the vapour pressure (in $bar$) of the solution?

The vapour pressure of ethanol $(C_2H_5OH)$ and methanol $(CH_3OH)$ at $298 \ K$ is $44.5 \ mm \ Hg$ and $88.7 \ mm \ Hg$ respectively. At the same temperature,an ideal solution is prepared by mixing $60 \ g$ of ethanol and $40 \ g$ of methanol. Find the mole fraction of methanol in the vapour state.

When a non-volatile solute is added to the solvent,the vapour pressure of the solvent decreases by $10 \ mm \ Hg$. The mole fraction of the solute in the solution is $0.2$. What would be the mole fraction of the solvent if the decrease in vapour pressure is $20 \ mm \ Hg$?

Calculate the vapour pressure of pure volatile liquid $B$ $(P_B^o)$ at a given temperature if the mole fraction of liquid $B$ $(x_B)$ is $0.4$ and the vapour pressure of pure volatile liquid $A$ $(P_A^o)$ is $400 \ mm \ Hg$. The total vapour pressure of the solution is $P_{total} = 600 \ mm \ Hg$. (in $mm \ Hg$)

$12 \ g$ of urea is dissolved in $1 \ L$ of water and $68.4 \ g$ of sucrose is dissolved in $1 \ L$ of water. The lowering of vapour pressure of the first case is