Question 1: Define a battery in terms of chemical energy and electrical energy.

Answer: A device that converts chemical energy into electrical energy through electrochemical reactions.

Question 2: Name two common types of rechargeable batteries used in portable electronic devices.

Answer: Lithium-ion and Nickel-Metal Hydride (NiMH) batteries.

Question 1: Explain the role of the electrolyte in a chemical cell.

Answer: The electrolyte allows the flow of ions between the electrodes, enabling the chemical reactions to produce electrical current.

Question 2: In a typical zinc-copper cell, which electrode is the anode and what is its oxidation state change during operation?

Answer: The zinc electrode is the anode; zinc atoms are oxidised to zinc ions, losing electrons.

Question 1: Calculate the total energy (in joules) produced by a battery that provides a current of 2.5 A over 3 hours. Use the formula: Energy (J) = Power (W) × Time (s). Assume the voltage of the battery is 1.5 V.

Answer: Energy = Voltage × Current × Time = 1.5 V × 2.5 A × 10800 s = 40,500 J

Question 1: List two safety precautions to observe when handling or disposing of chemical batteries.

Answer: Avoid short-circuiting the batteries and dispose of them according to hazardous waste regulations.

Question 2: Describe a simple experiment to test the voltage of a household battery, including the variables you would control.

Answer: Use a voltmeter to measure the voltage across the battery terminals. Control variables include ensuring the voltmeter is correctly calibrated, the battery is fresh and not connected to other devices, and the measurement is taken in a stable environment.

Question 1: A rechargeable lithium-ion battery has a capacity of 3000 mAh and operates at 3.7 V. Calculate the total energy stored in the battery in watt-hours (Wh).

Answer: Energy = Capacity (Ah) × Voltage (V) = 3 Ah × 3.7 V = 11.1 Wh

Question 2: Explain how the development of rechargeable batteries has impacted portable technology and renewable energy storage.

Answer: Rechargeable batteries have enabled the widespread use of portable electronic devices such as smartphones and laptops, reducing waste and cost. They are essential for renewable energy storage systems, allowing excess energy from solar and wind power to be stored for later use, thus supporting sustainable energy solutions.