Question

Given the balanced equation representing a redox reaction:

2Al + 3Cu2+ --> 2Al3+ + 3Cu
Which statement is true about this reaction?
(1) Each Al loses 2e- and each Cu2+ gains 3e-
(2) Each Al loses 3e- and each Cu2+ gains 2e-
(3) Each Al3+ gains 2e- and each Cu loses 3e-
(4) Each Al3+ gains 3e- and each Cu loses 2e-

Answer 1

The correct answer is option (2) i.e. Each Al loses 3e- and each Cu^2+ gains 2e- When an atom X, loses an electron, it becomes, X^1+ When an atom X, loses two electrons, it becomes, X^2+ When an atom X, gains an electron, it becomes, X^1- When an atom X, gains two electrons, it becomes, X^2- So, Here, 2Al + 3Cu^2+ --> 2Al^3+ + 3Cu, When each Al, loses three electrons, it becomes, Al^3+ When each Cu^2+, gains two electrons, it becomes, Cu^2+^2- = Cu

Answer 2

From the given balanced chemical reaction, it can be seen that each aluminum atom gains loses 3 electrons. Also, each copper atoms gains 2 electrons. The choice that would best give us the described scenario above is choice number 2. That is Each Al loses 3e- and each Cu gains 2e-.