Question 1: Halides are ions formed when a halogen atom gains an electron, resulting in a negative charge. Common halide ions include chloride (Cl⁻), bromide (Br⁻), and iodide (I⁻). They are commonly tested in the laboratory using silver nitrate solution, which forms precipitates that help identify them.

Answer: Halides are negatively charged ions formed from halogen atoms; tested using silver nitrate which produces distinctive precipitates.

Question 1: Describe the general procedure for testing a solution for the presence of halide ions using silver nitrate.

Answer: Add silver nitrate solution to the sample; observe the color and form of the precipitate to identify the halide.

Question 2: What is the typical precipitate color for each of the following halides when tested with silver nitrate? - Chloride - Bromide - Iodide

Answer: Chloride: White; Bromide: Cream; Iodide: Yellow

Question 3: Explain why silver nitrate is used in halide tests instead of other reagents.

Answer: Because silver nitrate forms insoluble precipitates with halide ions, which have distinctive colors, making identification easier.

Question 1: Calculate the concentration (in mol/L) of a chloride solution if adding 25 mL of it produces 0.045 g of white precipitate of silver chloride (AgCl). (Molar mass of AgCl = 143.32 g/mol)

Answer: Concentration = (mass / molar mass) / volume in liters = (0.045 g / 143.32 g/mol) / 0.025 L ≈ 0.0126 mol/L

Question 2: Design a simple experiment to test for halide ions in a water sample, including variables and safety precautions.

Answer: Add a few drops of water sample to a test tube, then add dilute nitric acid followed by silver nitrate solution. The formation of a precipitate indicates the presence of halides. Variables include the concentration of reagents and temperature. Safety precautions include wearing gloves and eye protection, and handling chemicals in a well-ventilated area.

Question 1: A sample of seawater tested positive for chloride ions, with a white precipitate forming upon addition of silver nitrate. Explain how this property is useful in industry or environmental monitoring.

Answer: Identifying chloride ions helps monitor water quality, detect pollution, and ensure safety in industries like water treatment and manufacturing.

Question 2: In the production of aluminum, why is understanding halide reactions important during the refining process?

Answer: Because halide reactions are involved in extracting aluminum from ores, and controlling these reactions improves purity and efficiency.