for how long must a current of 1.5 amperes be passed through an aqueous solution of a copper salt during electrolysis in order to deposit 2.50g of copper (cu=63.5)

Answer 1

It will require 95,485 coulombs to deposit 63.5/2 = 31.8 g Cu. You want 2.5 g Cu so it will require 96,485 C x (2.5/31.8 = 0.787 Coulombs.
C = amperes x seconds. You know C and amperes, calculate seconds.