What is the standard potential of a galvanic (voltaic) cell where X is the anode and Y is the cathode?

Question

Consider these two entries from a fictional table of standard reduction potentials.

X^3+ + 3e−⟶X(s) E°= −1.78 V

Y^3+ + 3e−⟶Y(s) E°= −0.23 V

What is the standard potential of a galvanic (voltaic) cell where X is the anode and Y is the cathode?

E° cell = ?

Answer 1

The standard potential of a galvanic cell (Eº) is calculated as follows:

Eº = reduction potential at cathode - reduction potential at anode

Eº = -0.23 V - (-1.78 V) = 1.78 V - 0.23 V

Eº = 1.55 V