Because of the common ion effect. Adding a common ion decreases the solubility of the salt which is the intention of a buffer.
Cu ions reduced to cu and Al oxidized to Al ions is the answer. copper ions is right hand side of the E.M.F cell where reduction take place and is reduced to copper metal. Al metal is at left hand side of the E.m.f cell where oxidation take place and is oxidized to Al ions
Answer:
The product is Methyl cyanoacetate
Explanation: see structure attached