Which of the following cells produce electrical energy from chemical reactions? l. Lead-acid battery ll. Dry cell III. Deniell cell IV Electrolytic cell

Step 1: Analyze the question We need to identify which cells convert chemical energy into electrical energy. These are called galvanic (voltaic) cells.

Step 2: The concept

• Galvanic/voltaic cells use a spontaneous redox reaction to produce electricity (chemical → electrical energy).
• Electrolytic cells do the opposite. They use electricity from an external source to force a non-spontaneous reaction (electrical → chemical energy).

Step 3: Check each cell

• I. Lead-acid battery: Produces electricity from the reaction between Pb, PbO₂ and H₂SO₄. It is a galvanic cell (it is recharged by electrolysis, but when in use it produces electrical energy). ✔
• II. Dry cell (Leclanché cell): Zinc is oxidized and MnO₂ is reduced, producing electricity. ✔
• III. Daniell cell: Zn/Cu cell with Zn²⁺/Cu²⁺ solutions, a classic galvanic cell. ✔
• IV. Electrolytic cell: Consumes electrical energy to cause chemical change. ✘

Step 4: Answer I, II and III produce electrical energy from chemical reactions, so the answer is B. I, II and III only.

Tip: Remember "Galvanic = Generates electricity", while "Electrolytic = Electricity is supplied". Any named battery or cell (dry cell, Daniell, lead-acid, car battery) is a source of power, while electrolysis (electroplating, extraction of metals) uses power.