× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
r
4
Home Q & A Board Science-Related Homework Help Chemistry (Moderator: Laser_3)
New Topic  
michaelg2547 michaelg2547
wrote...
Posts: 7
Rep: 0 0
11 years ago
0.206 moles of a salt of the general composition M1X1 are dissolved in 545.538 grams of water (Kf = 1.86 K·kg/mol).  Assuming that the salt completely dissociates into individual ions, what is the freezing point of the solution (in °C)?  Assume the pressure to be 1 atm.
Read 333 times
1 Reply

Related Topics

Replies
wrote...
#1
11 years ago
(delta)T = i x k x m

where (delta)T is the change in freezing point, i is the van't Hoff factor, k is the freezing point depression constant, and m is the molality

The MX ionic salt will dissociate to produce 2 ions per mole, so you should multiply by 2. The van't Hoff factor is 2.

molality = 0.206 mol divided by 0.545538 kg water to give a molality of 0.378.

(delta)T = (2)(1.86)(0.378) = 1.4

So the solution would freeze at a temp of NEGATIVE 1.4 degrees Celsius.
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  957 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 290
  
 177
  
 306
Your Opinion
Which is the best fuel for late night cramming?
Votes: 145
Previous poll results: What's your favorite funny biology word?