Question

Which of the following aqueous solution has highest freezing point?

• A. 0.1 molal $A{l}_2(S{O}_4{)}_3$
  
• B. 0.1 molal $BaC{l}_2$
• C. 0.1 molal $AlC{l}_3$
• D. 0.1 molal $N{H}_{4}Cl$

Answer 1

The correct option is D 0.1 molal $N{H}_{4}Cl$

The depression in freezing point is directly proportional to the number of non-volatile solute particles present. So, the solution that has the least number of particles would show the highest freezing point.
$N{H}_{4}Cl$ , i=2 produces the least number of ions among the ones given in the question.