Exams › NEET › Chemistry

Among the following, the couple with most positive reduction potential is :

1. \( M n^{+3} / M n^{+2} \)
2. \( C r^{+3} / C r^{+2} \)
3. \( F e^{+3} / F e^{+2} \)
4. \( C o^{+3} / C o^{+2} \)

Correct answer: \( C o^{+3} / C o^{+2} \)

Solution

A more positive reduction potential means the +3 ion is more easily reduced to +2. Among these couples, Co(III) is especially unstable relative to Co(II), so Co^{3+} gains an electron most readily. Therefore Co^{3+}/Co^{2+} has the highest reduction potential.

Related NEET Chemistry questions

• Assertion: When an electric current is passed through the copper sulphate electrolyte, the impure copper anode gradually dissolve and pure copper is deposited on the cathode. Reason: Pure metals are deposited in electroplating techniques.
• What is the electric current required to deposit 0.972 g of chromium in three hours? (E.C.E. of chromium is 0.00018 g/c)
• Which of the following statement (s) differentiate between electrochemical cell and electrolytic cell? This question has multiple correct options
• The resistance of \( 1 \mathrm{N} \) solution of acetic acid is \( 250 \Omega \) when measured in a cell having a cell constant of \( 1.15 \mathrm{cm}^{-1} . \) The equivalent conduction (in oh \( m^{-1} c m^{2} e q u i v^{-1} \) ) of \( 1 N \) acetic acid is
• If \( 9 g m H_{2} O \) is electrolysed completely with the current of \( 50 \% \) efficiency then :
• In which reactants are not contained within the cell but are continuously supplied from external source?

⚔️ Practice NEET Chemistry free + battle 1v1 →