An aqueous metal nitrate [M(NO3)₃] solution was subjected to electrolysis using a current of 25.0 A. If 408 g of the metal is produced in 400 min, what is the identity of the metal ion (M³⁺)?

• A. Ga³⁺
• B. Cr³⁺
• C. Au³⁺
• D. Fe³⁺

Answer: (C)