Help calculating this?
The boiling point of an aqueous solution is 102.17 °C. What is the freezing point?

Question

Help calculating this?
The boiling point of an aqueous solution is 102.17 °C. What is the freezing point?

anonymous · Answer

Also, how do I even begin this problem without knowing the element(s)?

aaronq · Answer

you don't need to know the element, the freezing point depression formula works on the basis of colligative properties.

use this formula:

$$DeltaT=iK _{f}m$$

find m, molality, using Kb

then plug into the same formula using the constant Kf

anonymous · Answer

Ka * Kb = Kw, correct?

aaronq · Answer

yeah but this is not related to acid and bases.

Kf is the freezing point depression constant, and Kb is the boiling point elevations constant

anonymous · Answer

I honestly have no idea how to even start this. Can you tell me what to do first?

aaronq · Answer

read my first reply

anonymous · Answer

Well, I guess I don't know how to tell the delta T. Is it 100 degrees less than the boiling point?

aaronq · Answer

if the boiling point is 102.17 °C, then dT is 2.17 °C

anonymous · Answer

So, 2.17=Kb(9649)(i)?

aaronq · Answer

you're solving for m first, then for dT using the other constant