Question 1: Define a chemical cell and explain how it produces electrical energy.

Answer: A chemical cell is a device that converts chemical energy into electrical energy through electrochemical reactions. It produces electrical energy by transferring electrons between electrodes via an external circuit.

Question 2: Describe the role of the electrolyte in a battery.

Answer: The electrolyte allows the flow of ions between the electrodes, completing the circuit and enabling the electrochemical reactions to continue.

Question 1: A typical AA battery has a voltage of 1.5 V and a capacity of 2000 mAh. Calculate the total energy stored in the battery in joules. (Use the formula: Energy (J) = Voltage (V) × Capacity (Ah) × 3600).

Answer: 10,800 joules

Question 2: If a rechargeable battery has a voltage of 3.7 V and a capacity of 2500 mAh, how much charge (in coulombs) can it deliver? (Use the relation: Charge (C) = Capacity (Ah) × 3600 × 1 Coulomb/1 Ah).

Answer: 9000 coulombs

Question 1: Outline the key safety precautions to observe when handling batteries during experiments.

Answer: Avoid short-circuiting batteries, handle with dry hands, do not puncture or damage batteries, and ensure proper disposal to prevent leaks or fires.

Question 2: Describe a simple experiment to test the voltage of different types of batteries and identify the variables involved.

Answer: Use a voltmeter to measure the voltage across the terminals of various batteries (e.g., AA, AAA, 9V). The independent variable is the type of battery; the dependent variable is the measured voltage. Control variables include the temperature and the state of charge of the batteries. Record and compare the voltages to determine their differences.

Question 1: A set of three batteries (Battery A: 1.5 V, 2000 mAh; Battery B: 1.2 V, 2500 mAh; Battery C: 1.5 V, 1500 mAh) are used to power a device. Which battery provides the most total energy? Show your calculations.

Answer: Battery B provides the most energy: 1.2 V × 2.5 Ah × 3600 = 10,800 J, compared to Battery A (1.5 V × 2 Ah × 3600 = 10,800 J) and Battery C (1.5 V × 1.5 Ah × 3600 = 8,100 J). So, Batteries A and B provide equal energy, which is more than C.

Question 2: A rechargeable battery shows a voltage of 3.7 V initially but drops to 3.2 V after partial discharge. What does this voltage change indicate about the battery's state? Explain briefly.

Answer: The voltage decrease indicates the battery's charge is being depleted, and it is approaching the end of its usable capacity. A voltage drop reflects reduced chemical energy available for conversion.

Question 1: Explain how lithium-ion batteries are used in electric vehicles and why they are preferred over traditional lead-acid batteries.

Answer: Lithium-ion batteries are used in electric vehicles because they have a high energy density, lightweight, and longer lifespan compared to lead-acid batteries. They can store more energy in a smaller size, which improves vehicle range and efficiency.

Question 2: Discuss the environmental impact of disposable batteries and suggest ways to reduce their negative effects.

Answer: Disposable batteries contain toxic metals and chemicals that can pollute soil and water if not disposed of properly. To reduce their impact, recycling programmes should be used, batteries should be recharged when possible, and alternative energy storage devices like rechargeable batteries should be preferred.