Assuming equal concentrations and complete dissociation, rank these aqueous solutions by their freezing points. nh4cl cobr3 k2so4

The freezing order from the largest to the smallest is:

NH4Cl> K2SO4> COBr3

For electrolyte solutions:

ΔTb = Kb.m. i

ΔTf = Kf.m. i

Kb = molal boiling point increase

Kf = molal freezing point constant

m = molal solution

i = van't Hoff factor

i = 1 + (n-1) α

The formula above shows that the freezing point depends on

•molal value

•degree of ionization/dissociation

•number of ions in solution

In the statement of the matter, it is known that there are solutions which have the same concentration and are completely dissociated (α = 1)

So the value of the freezing point drop depends only on the number of ions in the solution

The more ions produced, the greater the value of the freezing point (the freezing point is smaller)

There are several solutions

•1. NH4Cl ionization:

NH4Cl ---> NH4+ + Cl-

There are 2 ions in the solution

•2. COBr3 ionization:

COBr3 ---> CO3++ 3Br-

There are 4 ions in the solution

•3. ionization K2SO4

K2SO4 ---> 2K ++ SO42-

There are 3 ions in the solution

So the order of freezing from the largest to the smallest is:

NH4Cl> K2SO4> COBr3

The freezing point of a solution

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Keywords: freezing point,  properties, van't Hoff factor

the answer is minerals.