200 50 50 Vapour pressure (kPa) 100 150 0 PTS PE A B P 25 50 75 100 125 Temperature (°C) 3.1 Define the term boiling point. Use the information given in the graph to answer the questions that follow. Write down the: (2) 3.2 3.2.1 Boiling point of liquid B 3.2.2 Liquid which remains a liquid at 115 °C 3.2.3 Liquid that is most likely to be water €€€ (1) (1) (1) 3.3 State the PHASE CHANGE that takes place at the stage when the vapour pressure is equal to atmospheric pressure. (1) 3.4 What happens to the temperature of a liquid during a phase change? Write down only INCREASES, DECREASES or REMAINS THE SAME. (1) 3.5 Explain the answer to QUESTION 3.4. (2) 3.6 Which liquid (A, B, C or D) has the weakest intermolecular forces? Give a reason for the answer. (3) ल 3.7 What is the relationship between vapour pressure of the liquid and temperature? (2) [14]​