This is for a phase catalysis lab experiment

Question

1. How is the phase transfer catalyst removed from the product? I said, by washing it with salt.

2. what purpose does washing with 15% (half-saturated) NaCl solution serve? I said, to remove bulk of water

3. There is a slight excess of sodium benzoate in the reaction. How is it removed from the product? I said, by boiling the reaction

4. Why is the benzoate anion a stronger nucleophile in 1-bromobutane than in water solution? I do not know this answer.

Please help. I have been trying to figure it out, and those were the answers I could come up with, and I am not sure if they are correct. The assignment is due tomorrow.

Thanks in Advance.