Chemistry questions....

Question

Solubility of CaCl2 in water at 0C is about 5.4 molar.If Kr=1.86,then the decrease in freezing point of 0.54 molar CaCl solution is...

 

A.3.0C

B.3.5C

C.4.0C

D.2.7C

E.2.0C

Answer 1

Freezing point is affected by the concentration of particles in the solution.  Since CaCl₂ forms 3 ions in solution with water, each mole of it contains 3 moles of particles.  So the freezing point is decreased by 3 * 0.54 * 1.86 = 3.0132 °C.

 

So the answer is A.