engineering chemistry MCQ #2785

engineering chemistry MCQ #2785

1. Question 1

   Q1. The E⁰ value for the Mn³⁺/Mn²⁺ couple is more positive than that for Cr³⁺/Cr²⁺ or Fe³⁺/Fe²⁺ due to

   • A) change from d⁵ to d⁴
   • B) change from d⁴ to d⁵
   • C) much larger 3rd ionisation energy of Mn
   • D) much smaller 3rd ionisation energy of Mn

   Answer: much larger 3rd ionisation energy of Mn

   Explanation: The large 3rd ionization energy for Mn (d⁵ to d⁴) makes E⁰ more positive.