Question 1: Define ionic bonding and explain how it occurs between metals and non-metals.

Answer: Ionic bonding is the electrostatic attraction between positively charged metal ions (cations) and negatively charged non-metal ions (anions). It occurs when metals lose electrons to become cations and non-metals gain electrons to become anions, resulting in a strong electrostatic force that holds them together.

Question 2: Describe the mechanism of how sodium and chlorine form an ionic bond.

Answer: Sodium (Na) loses one electron to form Na⁺ (cation), while chlorine (Cl) gains one electron to form Cl⁻ (anion). The electrostatic attraction between Na⁺ and Cl⁻ results in an ionic bond, creating sodium chloride (NaCl).

Question 1: Calculate the number of electrons transferred when 2 moles of sodium atoms form ionic bonds with 2 moles of chlorine atoms.

Answer: Each sodium atom loses 1 electron, and each chlorine atom gains 1 electron. For 2 moles, total electrons transferred = 2 moles × 1 electron = 2 moles of electrons.

Question 2: If the lattice energy of sodium chloride is -787 kJ/mol, estimate the energy change when 3 moles of NaCl are formed from Na and Cl atoms.

Answer: Energy change = 3 mol × (-787 kJ/mol) = -2361 kJ.

Question 1: Describe a safe laboratory procedure to test if a compound forms ionic bonds with water.

Answer: Dissolve a small sample of the compound in water and observe if it dissociates into ions, indicated by electrical conductivity or pH change. Always wear safety goggles and gloves, and handle acids or salts carefully.

Question 2: Identify variables that could affect the formation of ionic bonds in a laboratory experiment.

Answer: Variables include temperature, purity of the substances, concentration of solutions, and presence of other ions or impurities.

Question 1: A sample of a compound contains 60% sodium and 40% chlorine by mass. Determine whether this compound could be sodium chloride, considering atomic masses of Na (23 g/mol) and Cl (35.5 g/mol).

Answer: Calculating molar ratios: Na = 23 g, Cl = 35.5 g. For 60 g Na, moles = 60/23 ≈ 2.61 mol; for 40 g Cl, moles = 40/35.5 ≈ 1.13 mol. The ratio is approximately 2.3:1, close to 1:1, indicating it could be NaCl.

Question 2: In an experiment, 5 grams of an unknown metal reacts with sulfur to form an ionic compound. The compound weighs 20 grams after reaction. What does this suggest about the nature of the bonding and the reaction?

Answer: Since the weight increases after reaction, sulfur has bonded to the metal, indicating ionic bonding. The formation involves transfer of electrons from the metal to sulfur, resulting in a stable ionic compound.

Question 1: Explain in detail the process of ionic bond formation between magnesium and oxygen, including electron transfer, ion formation, and the resulting structure. (6 marks)

Answer: Magnesium (Mg) loses two electrons to form Mg²⁺ ions, while oxygen (O) gains two electrons to form O²⁻ ions. The electrostatic attraction between Mg²⁺ and O²⁻ ions results in an ionic bond, creating magnesium oxide (MgO). The ions arrange in a lattice structure, maximizing attraction and minimizing repulsion, which gives the compound its high melting point and stability.

Question 1: Explain how ionic bonding is utilized in the manufacturing of table salt and its significance in daily life.

Answer: Ionic bonding in sodium chloride provides the solid, crystalline structure of table salt. Its solubility in water, due to ionic dissociation, makes it essential for flavoring and preserving food, as well as in chemical industries.