Answer:   
 
Explanation:
Depression in freezing point is given by:

 = Depression in freezing point
 = Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte like urea)
 = freezing point constant =
 = freezing point constant = 
m= molality

Weight of solvent (X)= 950 g = 0.95 kg  
Molar mass of non electrolyte (urea) = 60.06 g/mol
Mass of non electrolyte (urea) added = ?


Thus  urea was dissolved.
 urea was dissolved.
 
        
             
        
        
        
Reactivity could be one also toxicity flammability ect
        
             
        
        
        
The method that can be used to separate the mixture is DISTILLATION.
Distillation is a separating technique that is used to separate mixture of liquids which have boiling points that are far apart. The mixture will be heated, the liquid with the lowest boiling point will boil over and can be collected over a condenser, thus separating the two liquids.
        
                    
             
        
        
        
B.
I think this is right. 
If it is not I apologize