Statement I: In an electrochemical cell, anode and cathode are, respectively, negative and positive β Electrochemistry Chemistry Question
Question
Statement I: In an electrochemical cell, anode and cathode are, respectively, negative and positive electrode. Statement II: At anode, oxidation takes place and at cathode reduction takes place.
π‘ Solution & Explanation
\textbf{Assertion (I):} In a galvanic cell, the cathode is the positive electrode and the anode is the negative electrode. \textbf{Reason (II):} In a galvanic cell, reduction occurs at the cathode and oxidation occurs at the anode. \textbf{Analysis:} \textbf{Statement I:} In a galvanic cell, chemical energy is converted to electrical energy. The anode undergoes oxidation and releases electrons into the external circuit, making it the negative terminal. The cathode undergoes reduction and accepts electrons, making it the positive terminal. β \textbf{Correct.} \textbf{Statement II:} It is true that reduction occurs at the cathode and oxidation at the anode in any electrochemical cell. β \textbf{Correct.} However, the polarity of the electrodes (positive/negative) in a galvanic cell is determined by the \textit{spontaneous flow of electrons due to the EMF generated} β it is not directly because reduction or oxidation occurs there. The type of reaction (reduction/oxidation) determines which is cathode/anode, but the \textit{polarity} arises from the spontaneous cell reaction. Statement II is correct but does not satisfactorily explain why the cathode is the positive terminal (not the negative terminal). \textbf{Answer: B} (Statement I correct, Statement II correct but does not explain Statement I)