The van't Hoff factor for $Ca(NO_3)_2$ is ...... .

For a dilute aqueous solution of glucose,the van't Hoff factor $(i)$ is:

The Van't Hoff factor of $Ca(NO_3)_2$ is

Which of the following $0.1 \ m$ aqueous solutions exhibits the highest osmotic pressure at $25^{\circ}C$?

Consider the following solutions:
$I$. $1 \ M$ glucose $(aq.)$
$II$. $1 \ M$ sodium chloride $(aq.)$
$III$. $1 \ M$ acetic acid in benzene
$IV$. $1 \ M$ ammonium phosphate $(aq.)$

Calculate the amount of $KCl$ $(M_w = 74.5 \ g \ mol^{-1})$ in grams required to depress the freezing point of $1000 \ g$ of water by $2 \ K$. (Given: $K_f = 1.86 \ K \ kg \ mol^{-1}$) (in $.0$)