Assuming equal concentrations and complete dissociation, rank these aqueous solutions by their freezing points. nh4cl na3po4 li2so4

By using the formula of depression in freezing, it can easily identify the rank of the given compounds.

where,

= freezing point depression

i = van 't Hoff factor (number of ions per individual molecule of solute)

m = molality of the solute

= molal freezing point

According to question, if concentration (m) and is same, then only van 't Hoff factor will change.

For , i = 2

For , i = 4

For , i= 3

Now, the solute with the largest i value results in low freezing point.

The highest value of i is 4 (), thus   has lowest freezing point.

And, has highest freezing point.

The order of freezing point is :

i believe the answer is three water molecules