Most Important Selected Qs for JEE AdvancedChemistryElectrochemistry
E _ A ³⁺ / Al ^0=-1.66 ~V and K _ sp of Al ( OH )₃=1.0 10⁻³³ . The reaction potential of above couple at pH =14 is:
Options
- A-2.31 V
- B+2.31 V
- C+1.01 V
- D-1.01 V
Correct answer
A. -2.31 V
Step-by-step solution
Al ³⁺+3 e Al K = 1 [ Al ³⁺ ] aligned & Al ( OH )₃ A ³⁺+3 OH ⁻ & pH =14, [ H ⁺ ]=1 10⁻¹⁴ aligned aligned & ( OH ⁻ )=1 M & K _ sp = [ Al ³⁺ ][1]^3 & ( Al ³⁺ )=1 10⁻³³ M aligned E = E ^ - 0.0591 3 1 [ Al ³⁺ ] aligned & =-1.66- 0.0591 3 10³³=-1.66- 0.0591 3 33 & =-2.31 ~V aligned