# If you want to lower waters freezing point by 23°C by adding #"MgF"_2#, what must the molality of the solution be?

##### 1 Answer

Jun 4, 2018

#### Explanation:

Change in freezing point is given by

Where

#"i ="# Van’t Hoff factor (#3# for#"MgF"_2# )#"K"_f ="# Freezing point constant (#"1.86°C/molal"# for water)#"m ="# Molality of solution