what is the boiling point of an aqueous solution that freezes at

Question

-67 degrees C?

I was given this answer
What is 100+6.7 (1.86/.52) ?

so 100+6.7 = 106.7
1.86/.52 = 3.58
is the .52 the Kb
I got the answer in the book I just don't understand how they got to it.

Answer 1

-.52 is the Kf. 1.86 is the Kb You need to understand the signs.

first, find the molality.

-6.7=-.52*m
m=6.7/.52

Now the bp

New bp=100+kb*m=100*1.86*(6.7/.52)

Answer 2

Thanks I under stank Kf but in my book it says that Kf is 0.512