What is the molality of a solution of a nonvolatile solute having a boiling point elevation of $7.15 \ K$ and a molal elevation constant of $2.75 \ K \ kg \ mol^{-1}$ (in $m$)?

When $3.3 \ g$ of an unknown substance is dissolved in $125 \ g$ of benzene (boiling point $80^\circ \text{C}$),the boiling point of the resulting solution is $80.66^\circ \text{C}$. What is the molar mass of the unknown substance? $(K_b = 3.28 \ \text{K kg mol}^{-1})$

The molal elevation boiling point constant for water is $0.513 \ ^{\circ}C \ kg \ mol^{-1}$. Calculate the boiling point of the solution if $0.1 \ mol$ of sugar is dissolved in $200 \ g$ of water. (in $^{\circ}C$)

Calculate the amount of water evaporated if $2.8 \ kg$ of $2 \ m$ $CaBr_2$ solution is heated to $110 \ ^oC$ at $1 \ atm$ .......... $gm$.
(Given: $K_b$ of water $= 0.5 \ K \ kg/mol$; Atomic mass of $Ca = 40$,$Br = 80$)

What will be the boiling point of $1 \ m$ urea solution in $K$ unit? $(K_b = 0.52 \ K \ kg \ mol^{-1})$

Boiling point of a $2\%$ aqueous solution of a non-volatile solute $A$ is equal to the boiling point of an $8\%$ aqueous solution of a non-volatile solute $B$. The relation between molecular weights of $A$ and $B$ is: