Question

Consider the following balanced equation:

Cu + 2H+ -->Cu2+ + H2

Which of the following statements is true?
a) H+ gains one electron and is reduced
b) H+ gains one electron and is oxidized
c) H+ loses one electron and is reduced
d) H+ loses one electron and is oxidized

Answer 1

H+ gains one electron and is reduced.

It goes from H+ to H, so it gains an electron. Gaining an electron is reduction.

Answer 2

Cu + 2H+ -->Cu2+ + H2

a) H+ gains one electron and is reduced

b) H+ gains one electron and is oxidized

c) H+ loses one electron and is reduced

d) H+ loses one electron and is oxidized

Here,

H+ is changing to H2

hence its oxidation number is changing from +1 to zero,

thats its getting reduced as the oxidation number is decreasing here.

H+ + 1 e- → H