#### Answer

You have to consider effective molality which takes into account how many particles of a solute dissociates in solution. Calcium nitrate dissociates into 3 particles , so its effective molality is 3m. Sodium nitirate dissociates into 2 particles, so its effective molality is 2m.

#### Work Step by Step

You have to consider effective molality which takes into account how many particles of a solute dissociates in solution. Calcium nitrate dissociates into 3 particles, so its effective molality is 3m. Sodium nitirate dissociates into 2 particles, so its effective molality is 2m.