Question

What is ∆G and when
​​​​​ to use it in problems

Answer 1

It is known as the Gibbs free Energy change for a reaction. And if it is negative the reaction is possible, and not possible when it is positive
when to use it?

• When you have to find the direction of reaction and when you have to see if the reaction is feasible or not.
• In formulae ΔG = ΔG^o + RT InQ. This is the relation between the Gibbs energy and reaction quotient.

• In case of galvanic cells. Gibbs energy change ΔG is related to the electrical work done by the cell.

  ΔG = -nFE_(cell) where n = no. of moles of electrons involved

  F = the Faraday constant

  E = emf of the cell

  If reactants and products are in their standard states ΔG^o = –nFE^o_cell
  
  
  If you do not know what is all this, kindly ask another query.