Question 1: Hydrogen is the lightest and most abundant chemical element in the universe. It is used in various industries, including fuel cells and chemical manufacturing. This worksheet explores how hydrogen gas can be identified and analysed through practical and theoretical methods.

Answer: Hydrogen is the lightest and most abundant element, used in industry and identified by its flammability and reaction with oxygen.

Question 1: Define hydrogen gas and describe one common method used to test for its presence in a laboratory setting.

Answer: Hydrogen gas is a colourless, flammable gas; it is tested by its squeaky pop test using a lit splint.

Question 2: Explain the mechanism behind the 'squeaky pop' test for hydrogen detection.

Answer: Hydrogen reacts with oxygen in the presence of a flame, producing water and a characteristic squeaky pop due to rapid combustion.

Question 1: If 2.0 grams of hydrogen gas are burned completely, calculate the volume of water produced at standard temperature and pressure (STP). (Molar mass of H2 = 2 g/mol, 1 mol of gas occupies 22.4 L).

Answer: Mass of H2 = 2 g; Moles of H2 = 2 g / 2 g/mol = 1 mol; Volume = 1 mol × 22.4 L = 22.4 L

Question 1: Describe a safe procedure to test for hydrogen gas in the laboratory, including safety precautions.

Answer: To test for hydrogen, collect the gas in a test tube, then bring a lit splint close to the opening. A squeaky pop indicates hydrogen presence. Safety precautions include working in a well-ventilated area, avoiding open flames near gas sources, and wearing safety goggles and gloves.

Question 2: Identify the variables that need to be controlled during a hydrogen test experiment.

Answer: Variables include the amount of hydrogen collected, the temperature, and the presence of other gases that might interfere with the test.

Question 1: A student collects a gas and tests it with a lit splint. A squeaky pop is heard. What does this tell you about the gas and its properties?

Answer: The gas is hydrogen, which is flammable and reacts explosively with oxygen, producing a squeaky pop when ignited.

Question 1: Explain why hydrogen gas is considered a clean fuel and discuss one potential challenge of using hydrogen as a fuel source.

Answer: Hydrogen is a clean fuel because it produces only water when burned, reducing pollution. Challenges include storage difficulties due to its flammability and low density, and the need for specialised infrastructure.

Question 1: Describe one way hydrogen gas is used in industry or technology today.

Answer: Hydrogen is used in fuel cells to generate electricity for transportation and portable power sources.

Question 2: Suggest a safety consideration that must be addressed when handling hydrogen in industrial settings.

Answer: Proper ventilation and leak detection systems are essential to prevent explosive accumulations of hydrogen.