Chemistry Help?

Question

Which of the following solutions would have the lower freezing temperature 0.1m NaCl or a 0.1m CaCl2? Explain your answer.

Answer 1

The depression of freezing point is directly proportional to the molal concentration of dissolved particles in the solution.

delta T = mkf n

kf for H2O is 1.86

When NaCl dissolves gives 2 ions ( Na+ and Cl-)

When CaCl2 dissolves gives 3 ions Ca2+ and 2 Cl-

deltaT = 0.1 ( 1.86 ) 2 = 0.372 for NaCl

delta T = 0.1 ( 1.86) 3 = 0.558 for CaCl2

the solution of CaCl2 has the lower f.p.

Answer 2

The depression of freezing points depends on the number of particles being molecules or ions
NaCl when dissociating gives 2 ions Na+ And Cl-, whereas CaCl2 gives three ions Ca++ and 2 Cl-. So as both are completely dissociated and the molarity is the same, CaCl2 gives a depression 1.5 higher than NaCl

Answer 3

Nacl dissociates in to Na+ D Cl- ions, Cacl2 dissociates in to
ca+ D 2moles of cl- ions ,both has same molarity cacl2 would have low freezing temperature