Question

Which aqueous solution has the highest boiling point?a. 0.20 M NaClb. 0.10 M CaCl2c. 0.1 M Ga2(SO4)3d. 0.2 M C6H12O6

Answer 1

Answer:

c. 0.1 M Ga₂(SO₄)₃

Explanation:

The boiling point increasing of a solvent due the addition of a solute follows the formula:

ΔT = K*m*i

Where K is boiling point increasing constant (Depends of the solute), m is molality = molarity when solvent is water, and i is Van't Hoff factor.

That means the option with the higher m*i will be the solution with the highest boiling point:

a. NaCl has i = 2 (NaCl dissociates in Na⁺ and Cl⁻ ions).

m* i = 0.20*2 = 0.4

b. CaCl₂; i = 3. 3 ions.

m*i= 0.10M * 3 = 0.3

c. Ga₂(SO₄)₃ dissolves in 5 ions. i = 5

m*i = 0.10M*55 = 0.5

d. C₆H₁₂O₆ has i = 1:

m*i = 0.2M*1 = 0.2

The solution with highest boiling point is:

c. 0.1 M Ga₂(SO₄)₃