Chemistry Lab Report – 3 small questions!

Hi.. I just have 3 small questions. Due tomorrow

Observations and Data 

(1 mark) Table 1: Masses of solvent and solute used 

Mass of sample vial and biphenyl : 15.534 g

Mass of sample vial emptied : 14.00 g 

Mass of biphenyl :2.110 g

Unknown number :2

Mass of sample vial and unknown: 13.440 g

Mass of emptied sample vial : 13.123 g

Mass of unknown added to the biphenyl: 0.240 g

(5 marks: for the interpretation of graphs and the data in Table 2) 

Table 2: Freezing point data and freezing point depression by unknown 

Freezing point of pure biphenyl from run 1: 68.1 celcies 

Freezing point of pure biphenyl from run 2 : 68.2 celcies 

Freezing point of pure biphenyl from run 3 : 68.2

Average freezing-point of pure biphenyl : 68.2

Freezing point of solution of unknown in biphenyl from run 1: 60.2 

Freezing point of solution of unknown in biphenyl from run 2 : 61.4

Freezing point of solution of unknown in biphenyl from run 3 : 60.5

Average freezing point of solution of unknown in biphenyl : 60.7

Freezing point depression : -7.4

1. (3 marks) Calculate the molality of the solution of the unknown in biphenyl. 

 

 

 

 2. (3 marks) Calculate the molar mass of the unknown

3. (3 marks) You will have been given one of the molecules depicted in the introduction as 

your unknown. Which do you believe it is? Base your choice on the experimental molar 

mass you calculated from your data, and comment on how certain you are of your 

identification