What will be the freezing point of a $1\%$ aqueous solution of $Ca(NO_3)_2$?

Pure water freezes at $273 \ K$ and $1 \ bar$. The addition of $34.5 \ g$ of ethanol to $500 \ g$ of water changes the freezing point of the solution. Use the freezing point depression constant of water as $2 \ K \ kg \ mol^{-1}$. The figures shown below represent plots of vapour pressure $(V.P.)$ versus temperature $(T)$. [molecular weight of ethanol is $46 \ g \ mol^{-1}$]. Among the following,the option representing the change in the freezing point is:

The freezing point of a diluted milk sample is found to be $-0.2\ ^\circ C$,while it should be $-0.5\ ^\circ C$ for pure milk. How much water has been added to pure milk to make the diluted sample?

Molal depression constant $(K_{f})$ is dependent on

What is observed during the depression of freezing point?

$40 \ g$ of glucose (Molar mass $= 180 \ g \ mol^{-1}$) is mixed with $200 \ mL$ of water. The freezing point of the solution is $..... \ K$. (Nearest integer)
[Given : $K_{f} = 1.86 \ K \ kg \ mol^{-1};$ Density of water $= 1.00 \ g \ cm^{-3};$ Freezing point of water $= 273.15 \ K$]