1.1. A student is given the following reagents and instructions to prepare a sample of 1-bromobutane, C₄H₉Br, (boiling point 102 ^oC).

Reagents

• Concentrated sulfuric acid

• Sodium bromide

• Butan-1-ol, C₄H₉OH

Procedure 

1. Place 5 g of crushed sodium bromide in a 100 cm³ round-bottomed flask containing 10 cm³ of distilled water and 5 cm³ of butan-1-ol (boiling point 117 ^oC). Swirl gently until the sodium bromide is dissolved.

2. Carefully add 6 cm³ of sulfuric acid. The sulfuric acid reacts with the sodium bromide to form hydrogen bromide. If the reaction mixture becomes too hot then cool the flask with cold water.

3. Fit a condenser, in reflux, to the flask and boil the reaction mixture for 30 minutes.

4. Allow the equipment to cool and rearrange it for distillation.

5. Gently heat the flask to distil the reaction mixture into a small conical flask. Collect the fraction that boils between 95 ^oC and 125 ^oC.

6. Add sodium hydrogen carbonate solution to the distillate and shake this mixture until no more gas is evolved. Two layer of liquid will form inside the conical flask.

7. Separate the two layers of liquid, collect the impure 1-bromobutane and wash it with water. Separate the water layer before drying the 1-bromobutane.

8. Re-distil the 1-bromobutane and collect the fraction that boils between 101 ^oC and 103 ^oC.

Suggest hazards for butan-1-ol and concentrated sulfuric acid.

1.2. Draw a diagram to show how you would set up the apparatus for distillation, required in step 4.

1.3. Suggest what impurities might be present within the fraction collected in step 5.

1.4. Write a balanced equation to explain the formation of the gas, in step 6.  

1.5. An equation for the reaction is shown below:

C₄H₉OH + HBr → C₄H₉Br + H₂O

Calculate the mass of 1-bromobutane that would be formed from 5.55 g of butan-1-ol, assuming a 50% yield.