please help me in the questions i've raised below in the preperation of bromoethane?

Question

1-why is it important to add sufficient amount of water in a flask to cover the delivery tube during the preperation of bromoethane.
2-why isn't it possible to obtain 100% yield of bromoethane during this experiment.
3-what are the safety aspects in this experiment(preperation of bromoethane)

Answer 1

1) Otherwise the product will be contaminated.

2) Its not possible in any reaction due to many side reactions.

3) The gas may ignite.