JEE Main202329 Jan 2023Morning ShiftChemistryElectrochemistryActual
The standard electrode potential ( M 3 + / M 2 + ) for V , Cr , Mn & Co are - 0 . 26 V , - 0 . 41 V , + 1 . 57 V and + 1 . 97 V , respectively. The metal ions which can liberate H 2 from a dilute acid are
Options
- AV 2 + and Mn 2 +
- BCr 2 + and Co 2 +
- CV 2 + and Cr 2 +
- DMn 2 + and Co 2 +
Correct answer
C. V 2 + and Cr 2 +
Step-by-step solution
The E ⊝ values for the redox couple ( M 3 + / M 2 + ) shows that Mn 2 + and Co 2 + ions are the strongest oxidising agents in aqueous solution. The ions Ti 2 + ,   V 2 +   and   Cr 2 + are strong reducing agents and will liberate hydrogen from a dilute acid. So, the Correct answer is V 2 +   and   Cr 2 + .