Question 1: Define the term 'salt' as used in chemistry.

Answer: A salt is an ionic compound formed when an acid reacts with a base, consisting of a positive metal or ammonium ion and a negative non-metal ion.

Question 2: Describe the general mechanism of producing a salt by neutralising an acid with an alkali.

Answer: An acid reacts with an alkali (base) in a neutralisation reaction, producing a salt and water. The acid's hydrogen ions combine with the hydroxide ions from the base to form water, leaving the remaining ions to form the salt.

Question 1: Calculate the mass of sodium chloride (NaCl) required to prepare 500 mL of a 0.1 mol/dm³ solution.

Answer: 5.85 grams

Question 2: If 25 mL of hydrochloric acid (HCl, concentration 0.5 mol/dm³) reacts completely with excess sodium hydroxide, how many moles of HCl are used?

Answer: 0.0125 mol

Question 1: List two safety precautions that should be taken when handling acids in the laboratory.

Answer: Wear appropriate personal protective equipment such as gloves and safety goggles; handle acids carefully to avoid spills and skin contact.

Question 2: Describe the general steps involved in preparing a soluble salt via titration and crystallisation.

Answer: First, titrate an acid with a base to determine the exact volume needed for neutralisation. Then, mix the acid and base in the correct ratio, and heat the solution to concentrate it. Next, allow the solution to cool slowly to form crystals of the salt. Finally, filter and dry the crystals for use.

Question 1: A student reacts 50 mL of 0.2 mol/dm³ sulfuric acid with excess sodium hydroxide. How many grams of sodium sulphate (Na₂SO₄) will be produced? (Molar mass of Na₂SO₄ = 142.04 g/mol)

Answer: 2.84 grams

Question 1: Explain how salts are used in the food industry, providing an example.

Answer: Salts like sodium chloride are used as preservatives and flavour enhancers in food products.

Question 2: Identify a use of salts in agriculture and describe its importance.

Answer: Salts like potassium nitrate are used in fertilisers to supply essential nutrients for plant growth, which is vital for crop production.