Voltaic cells produce a positive overall cell potential. what does this indicate?

Explanation:

Voltaic cell is a cell in which a chemical reaction occurs that leads to generation of electricity.

To calculate cell potential of a voltaic cell, the formula is as follows.

                                    = +ve

Also, a positive cell potential indicates that a reaction is spontaneous as follows.

                      = - nF

                              = (-ve)(+ve)

                              = -ve

Therefore, value of comes out to be -ve. Therefore, it shows that when voltaic cells produce a positive overall cell potential then the reaction is spontaneous.