Calculating Freezing and Boiling Points

[viper2308]

Homework Statement

Calculate the freezing point and boiling point of each of the following solutions using the observed van't Hoff factors in Table 11.6.

(a) 0.070 m MgCl2
Temp Freezing?

Temp Boiling?


(b) 0.020 m FeCl3
Temp Freezing?

Temp Boiling?

Homework Equations

Change in T= imK
i=Van't Hoff factor
m=given
K=freezing point depression or boiling point elevation

The Attempt at a Solution

I don't know what the change in temp is so I can't solve for K.
Tf MgCl2- Change in T= (3)(.07)K Don't know K or T

 

[Vagrant]

∆Tb=New boiling point-Boiling point of pure solvent
∆Tf=Freezing point of pure solvent-New freezing point,
now knowing boiling/freezing point of the pure solvent, i, m and K(which will be given) you can find the new boiling/ freezing point.

 

[Gokul43201]

K is a property of the solvent. It has a specific value for every solvent, and can be looked up in your textbook, or a handbook, or on the web.

See the tables on this page: http://dbhs.wvusd.k12.ca.us/webdocs/Solutions/BP-Elev-and-FP-Lower.html