Which of the following changes will cause an increase in the vapour pressure of a $1 \ m$ aqueous $KI$ solution at the same temperature?

$A$ solution is obtained by dissolving $12 \ g$ of urea (mol.wt. $60$) in a litre of water. Another solution is obtained by dissolving $68.4 \ g$ of cane sugar (mol.wt. $342$) in a litre of water at the same temperature. The lowering of vapour pressure in the first solution is

$100 \, g$ of liquid $A$ (molar mass $140 \, g \, mol^{-1}$) was dissolved in $1000 \, g$ of liquid $B$ (molar mass $180 \, g \, mol^{-1}$). The vapour pressure of pure liquid $B$ was found to be $500 \, torr$. Calculate the vapour pressure of pure liquid $A$ and its vapour pressure in the solution if the total vapour pressure of the solution is $475 \, torr$.

An aqueous solution is $1.00 \ molal$ in $KI$. Which change will cause the vapour pressure of the solution to increase?

$5 \ cm^3$ of acetone is added to $100 \ cm^3$ of water. The vapour pressure of water over the solution:

At $300 \ K$,the vapour pressure of a solution containing $1 \ mole$ of $n-hexane$ and $3 \ moles$ of $n-heptane$ is $550 \ mm \ Hg$. At the same temperature,if one more mole of $n-heptane$ is added to this solution,the vapour pressure of the solution increases by $10 \ mm \ Hg$. What is the vapour pressure in $mm \ Hg$ of $n-heptane$ in its pure state?