The EMF of the cell Al / Al ³⁺(0.01 M ) | Fe ²⁺(0.02 M ) / Fe is 1.209 V . The EMF of the cell can be increased by ------------------------------

Step-by-step solution

The cell reaction is 2 Al (s) + 3 Fe ²⁺(aq) 2 Al ³⁺(aq) + 3 Fe (s) . The Nernst equation for the cell EMF is given by E_ cell = E⁰_ cell - 0.0591 n Q , where Q = [ Al ³⁺]^2 [ Fe ²⁺]^3 and n = 6 . Substituting the expression for Q : E_ cell = E⁰_ cell - 0.0591 6 ( [ Al ³⁺]^2 [ Fe ²⁺]^3 ) . To increase E_ cell , the value of the term ( [ Al ³⁺]^2 [ Fe ²⁺]^3 ) must be decreased. This can be achieved by either decreasing the numerator [ Al ³⁺] or increasing the denominator [ Fe ²⁺] . Among the given options, increasing