Question 1: Chemical energy is stored within the bonds of chemical compounds. When these bonds are broken during a chemical reaction, energy is released or absorbed. This form of energy is vital in powering engines, batteries, and biological processes.

Answer: Chemical energy is stored in the bonds of chemical compounds and is released or absorbed during chemical reactions.

Question 1: Define chemical energy in your own words.

Answer: Chemical energy is the energy stored in the bonds of atoms and molecules that can be released during chemical reactions.

Question 2: Explain why chemical energy is considered a form of potential energy.

Answer: Because it is stored within chemical bonds and has the potential to be released during reactions, making it a form of potential energy.

Question 1: A battery stores 200 kJ of chemical energy. If 60% of this energy is converted into electrical energy during use, how much electrical energy is produced? Use the formula: Energy output = Total chemical energy × efficiency.

Answer: 120 kJ

Question 2: Calculate the amount of chemical energy stored in 50 grams of a substance that releases 5 kJ per gram during a reaction. Use the formula: Total energy = mass × energy per gram.

Answer: 250 kJ

Question 1: Describe a simple experiment to demonstrate the release of chemical energy in a reaction. Include the key variables involved and safety precautions.

Answer: One example is burning a small piece of magnesium ribbon to demonstrate energy release. Variables include the amount of magnesium and oxygen. Safety precautions involve wearing safety goggles, handling magnesium with tongs, and performing the experiment in a well-ventilated area.

Question 1: A chemical reaction releases 350 kJ of energy when 100 grams of a fuel undergoes combustion. Determine the energy released per gram of fuel. Use the formula: Energy per gram = Total energy / mass.

Answer: 3.5 kJ per gram

Question 2: If a device requires 150 kJ of chemical energy to operate, how many grams of the fuel described above are needed? Use the formula: mass = total energy / energy per gram.

Answer: Approximately 43 grams

Question 1: Explain how chemical energy is utilized in everyday batteries and discuss one advantage and one disadvantage of using chemical energy sources.

Answer: Batteries store chemical energy that is converted into electrical energy when in use. An advantage is portability and ease of use; a disadvantage is limited lifespan and potential environmental harm from disposal.

Question 2: Identify a technological application that relies on chemical energy and describe how this energy is converted for use in the device.

Answer: Chemical energy in fuel cells is converted into electrical energy to power vehicles.