Question 1: Define a giant covalent structure and give two examples.

Answer: A giant covalent structure is a large network of atoms bonded together by covalent bonds, forming a continuous lattice. Examples include diamond and graphite.

Question 2: Describe the main difference between the bonding in diamond and graphite.

Answer: In diamond, each carbon atom forms four strong covalent bonds in a tetrahedral structure, creating a rigid 3D network. In graphite, each carbon atom bonds to three others in layers with weak forces between layers.

Question 3: Calculate the amount of energy required to break all covalent bonds in 1 mole of diamond, given that the average energy per C–C covalent bond is 348 kJ/mol and each diamond molecule contains 6 bonds.

Answer: Total energy = Number of bonds per molecule x energy per bond x number of molecules = 6 bonds x 348 kJ/mol = 2088 kJ for 1 mole of diamond.

Question 4: Propose a practical experiment to compare the thermal conductivity of diamond and graphite. List the variables involved and safety precautions.

Answer: Experiment: Use small samples of diamond and graphite, place each on a heat source, and measure the temperature change over time with a thermometer. Variables: type of material (independent), temperature change (dependent), heat source (controlled). Safety precautions include wearing heat-resistant gloves and eye protection to handle hot materials.

Question 5: In a scenario where a layer of graphite is used in a pencil, explain how its structure benefits its function.

Answer: Graphite's layers can slide over each other due to weak forces between layers, making it a good lubricant and suitable for writing because it leaves a streak on paper.

Question 6: Which property of diamond makes it suitable for use in cutting tools?

Answer: Very hard due to strong covalent bonds

Question 7: Fill in the blank: The layers in graphite are held together by __________ forces, which are __________ than covalent bonds.

Answer: weak, weaker

Question 8: Explain why diamond is transparent while graphite is opaque.

Answer: Diamond's rigid 3D network of covalent bonds allows light to pass through with minimal absorption, making it transparent. Graphite's layered structure absorbs and scatters light, making it opaque.

Question 9: Describe the industrial uses of giant covalent structures and explain why their properties are suitable for these applications.

Answer: Giant covalent structures like diamond are used in cutting tools and abrasives because of their hardness. Graphite is used as a lubricant and in batteries because of its electrical conductivity and layered structure. These properties stem from their strong covalent bonds and layered arrangements, making them durable and functional in various industries.