Question 1: Define a simple molecule and explain how covalent bonding contributes to its stability.

Answer: A simple molecule consists of a small number of atoms held together by covalent bonds. Covalent bonding involves the sharing of electron pairs between atoms, which results in a stable molecular structure.

Question 2: Name two common simple molecules used in industry and briefly describe their uses.

Answer: Water (H₂O) used as a solvent and in chemical reactions; Ammonia (NH₃) used in fertilisers and cleaning products.

Question 1: Explain why molecules like H₂ and Cl₂ are considered simple molecules.

Answer: They consist of only two atoms bonded covalently, with no complex structures or multiple atoms involved, making them simple molecules.

Question 2: Describe the mechanism of covalent bond formation between two non-metal atoms.

Answer: Non-metal atoms share electron pairs to achieve a full outer shell, forming a covalent bond that holds the atoms together in a molecule.

Question 1: Calculate the number of molecules in 2 moles of water (H₂O). (Use Avogadro's number: 6.022 × 10²³ molecules per mole).

Answer: Number of molecules = 2 moles × 6.022 × 10²³ molecules/mole = 1.2044 × 10²⁴ molecules.

Question 2: Determine the molar mass of ammonia (NH₃) and explain its significance in calculations.

Answer: Molar mass of NH₃ = (14.0 for N) + 3 × (1.0 for H) = 17.0 g/mol. It is used to convert between mass and moles in chemical calculations.

Question 1: Describe a basic experimental setup to test the purity of a sample of water in an industrial setting, including key variables and safety precautions.

Answer: The setup involves distillation or chromatography to test purity, controlling variables like temperature, flow rate, and contamination sources. Safety precautions include wearing protective gloves, goggles, and working in a well-ventilated area to handle chemicals safely.

Question 1: A factory produces 500 kg of ammonia per day. If the molar mass of ammonia is 17.0 g/mol, how many moles are produced daily? Show your calculations.

Answer: Total moles = 500,000 g ÷ 17.0 g/mol = approximately 29,411.76 moles.

Question 2: Interpret the significance of the molar amount of ammonia produced in terms of industrial efficiency and raw material consumption.

Answer: A higher molar production indicates efficient use of raw materials and effective synthesis processes, essential for meeting industrial demand and cost management.

Question 1: Explain how the covalent bonding in methane (CH₄) affects its use as a fuel in industry.

Answer: Covalent bonds in methane are strong and stable, allowing it to release a significant amount of energy when combusted, making it an efficient and reliable fuel source in industry.

Question 2: Identify two environmental concerns related to the industrial use of simple molecules such as sulphur dioxide (SO₂).

Answer: Sulphur dioxide contributes to acid rain and air pollution, which can harm ecosystems and human health.