[2clients]

Hello,

I'm new here.  I'm taking General Chemistry II after not having chemistry for a while.  I've been stumped by the following question.  I think colligative properties come into play here but I'm not sure how.  I know that freezing point is lowered as concentration increases, but how do I compare the same molalities below?

Which of the following aqueous solutions should have the lowest freezing point?

1. 1 m NH3
2. 1 m C6H12O6
3. pure H2O
4. 1 m RbI
5. 1 m MgBr2

[Arkcon]

Recheck the description for colligative properties in your textbook, does it say concentration, or does it use some other word.  That's a hint.

[2clients]

Thank you. So, I think it must be the total molality and ions must be considered?  I think that MgBr2 is the answer, because it would have the most particles, 3, in solution?

[macman104]

Very good!

[2clients]

Yes!

Thank you!