Q21.8P - Chemistry: Molecular Nature Of Matter And Change

Question

Which type of electrochemical cell has  ${\mathbf{\Delta G}}_{\mathbf{sys}\mathbf{ }}\mathbf{<}\mathbf{0}$? Which type shows an increase in free energy?

Step-by-Step Solution

Answer

For voltaic cells, use the ${\mathrm{\Delta G}}_{\mathrm{sys} }<0$

For electrolytic cells, use ${\mathrm{\Delta G}}_{\mathrm{sys}}>0$

Step 1: Definition of an electrochemical cell

An electrochemical cell is a device that uses chemical reactions to create a potential difference between electrodes. Electrochemical cells include galvanic cells and electrolytic cells. 

Step 2: The probability if all three family members are assigned to the same station

Voltaic cells (also known as Galvanic cells) have a  ${\mathrm{\Delta G}}_{\mathrm{sys} }<0$ and thus exist naturally.

Electrolytic cells, on the other hand, show an increase in free energy, implying that they involve non-spontaneous processes for which ${\mathrm{\Delta G}}_{\mathrm{sys}}>0$.