Answer : The voltage of galvanic cell made with zinc and aluminum is, 0.90V
Explanation :
We are taking the value of standard reduction potential form the standard table.
![E^0_{[Al^{3+}/Al]}=-1.66V](https://tex.z-dn.net/?f=E%5E0_%7B%5BAl%5E%7B3%2B%7D%2FAl%5D%7D%3D-1.66V)
![E^0_{[Zn^{2+}/Zn]}=-0.76V](https://tex.z-dn.net/?f=E%5E0_%7B%5BZn%5E%7B2%2B%7D%2FZn%5D%7D%3D-0.76V)
In this cell, the component that has lower standard reduction potential gets oxidized and that is added to the anode compartment. The second forms the cathode compartment.
The half oxidation-reduction reaction will be :
Oxidation :
![E^0_{[Al/Al^{3+}]}=1.66V](https://tex.z-dn.net/?f=E%5E0_%7B%5BAl%2FAl%5E%7B3%2B%7D%5D%7D%3D1.66V)
Reduction :
![E^0_{[Zn^{2+}/Zn]}=-0.76V](https://tex.z-dn.net/?f=E%5E0_%7B%5BZn%5E%7B2%2B%7D%2FZn%5D%7D%3D-0.76V)
The expression for standard cell is,

![E^0=E^0_{[Al/Al^{3+}}+E^0_{[Zn^{2+}/Zn]}](https://tex.z-dn.net/?f=E%5E0%3DE%5E0_%7B%5BAl%2FAl%5E%7B3%2B%7D%7D%2BE%5E0_%7B%5BZn%5E%7B2%2B%7D%2FZn%5D%7D)


Therefore, the voltage of galvanic cell made with zinc and aluminum is, 0.90 V