Question

.. What does the negative sign in the expression E Zn2+/Zn = -0.76 V mean?​

Answer 1

By convention, all standard electrode potentials are reduction potentials. A positive value suggests that the reduced form of the species is more stable than hydrogen gas and a negative value suggests that the hydrogen gas is more stable than the reduced form of species. ... It is difficult to reduce Zn2+ to Zn.