Question 1: Explain how chemical cells (batteries) can contribute to renewable energy storage.

Answer: Chemical cells store energy produced from renewable sources like solar and wind, allowing energy to be used when generation is low. They convert chemical energy into electrical energy through electrochemical reactions.

Question 1: Define a galvanic cell and describe its basic working mechanism.

Answer: A galvanic cell is a device that converts chemical energy into electrical energy through spontaneous redox reactions, involving two electrodes immersed in electrolyte solutions.

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

Answer: The electrolyte allows ions to move between electrodes, completing the circuit and enabling the redox reactions that generate electrical current.

Question 1: Calculate the voltage of a cell if the standard reduction potentials are: Zn²⁺/Zn = -0.76 V and Cu²⁺/Cu = +0.34 V.

Answer: 0.34 - (-0.76) = 1.10 V

Question 2: A lithium-ion battery has a capacity of 3.0 Ah and operates at 3.7 V. Calculate its total energy storage in watt-hours (Wh).

Answer: Energy = capacity (Ah) × voltage (V) = 3.0 × 3.7 = 11.1 Wh

Question 1: Outline the steps to set up a simple electrochemical cell experiment to compare the voltages of different metal electrodes.

Answer: First, gather different metal electrodes (e.g., zinc, copper, magnesium), a suitable electrolyte solution, and a voltmeter. Clean the electrodes thoroughly, then connect each pair of electrodes in the electrolyte with leads to the voltmeter. Record the voltage readings for each pair, ensuring safety precautions such as wearing gloves and eye protection. Keep the electrolyte away from skin and eyes, and dispose of solutions responsibly afterward.

Question 2: Identify the key variables that would affect the voltage output in a battery experiment and suggest safety precautions.

Answer: Variables include electrode material, electrolyte concentration, temperature, and electrode surface area. Safety precautions include wearing protective gear, handling chemicals carefully, and ensuring proper disposal of chemicals.

Question 1: A portable solar-charged battery system is rated at 100 Wh. If it supplies a device consuming 10 W, how long can it operate continuously?

Answer: Time = Energy / Power = 100 Wh / 10 W = 10 hours

Question 2: Explain how rechargeable batteries contribute to reducing reliance on fossil fuels in renewable energy systems.

Answer: Rechargeable batteries allow excess renewable energy, such as from solar panels or wind turbines, to be stored for later use, reducing the need for fossil fuel-based power generation. They facilitate a steady energy supply, promote grid stability, and support the transition to cleaner energy sources, thereby decreasing greenhouse gas emissions.

Question 1: Evaluate the advantages and disadvantages of using lithium-ion batteries in renewable energy storage. Include environmental and economic factors in your answer.

Answer: Advantages of lithium-ion batteries include high energy density, long cycle life, and efficiency, making them suitable for large-scale energy storage. They enable effective integration of renewable sources like solar and wind. Disadvantages include environmental concerns due to mining of lithium and other materials, potential safety hazards such as thermal runaway, and high manufacturing costs. Recycling and sustainable sourcing are ongoing challenges that impact their environmental footprint. Economically, while initial costs are high, decreasing prices and longer lifespans improve their viability for renewable energy applications.