Halide reactions and predicting halogen chemistryEdexcel International A Level Chemistry: Flashcards
What these 13 flashcards ask
- What forms when a solid sodium halide is warmed with concentrated sulfuric acid in the first step?
- What is seen with solid NaCl and concentrated H₂SO₄?
- Give the products of NaBr with concentrated H₂SO₄.
- Give the sulfur products when NaI reacts with concentrated H₂SO₄.
- What is the change in oxidation number of sulfur on forming H₂S?
- State the trend in reducing ability of the halide ions.
- Why is iodide a stronger reducing agent than chloride?
- Why is nitric acid added before silver nitrate?
- Give the colours of AgCl, AgBr and AgI.
- Which silver halides dissolve in dilute and concentrated ammonia?
- What happens when HCl meets NH₃ gas?
- What would NaF give with concentrated H₂SO₄ and with AgNO₃?
- Predict the appearance of astatine and silver astatide.
Exam questions on Halide reactions and predicting halogen chemistry
- A technician tests three unlabelled solid sodium halides, each known to be sodium chloride, sodium bromide or sodium iodide. In a fume cupboard she adds a few drops of concentrated sulfuric acid to a small sample of each and records what happens.Explain why iodide ions reduce concentrated sulfuric acid but chloride ions do not.2 marks
- A student adds aqueous silver nitrate, acidified with dilute nitric acid, to separate aqueous solutions of potassium chloride, potassium bromide and potassium iodide. She then tests how each precipitate behaves with aqueous ammonia.Explain why dilute nitric acid is added to the halide solution before the silver nitrate.2 marks
- Hydrogen chloride gas is made in the laboratory by warming solid sodium chloride with excess concentrated sulfuric acid. In one experiment the gas is passed into a gas jar of ammonia gas. In another it is bubbled into water. Take the molar volume of a gas at room temperature and pressure as 24 dm³ mol⁻¹.State what is seen when hydrogen chloride gas meets ammonia gas, write the equation for the reaction and state the role of the ammonia.3 marks
Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).