A solid sodium halide, NaX\text{NaX}NaX, undergoes the following reactions:
Which of the following correctly identifies the halide ion, X−\text{X}^-X−, and the role of sulfuric acid in the redox reaction that produces the orange-brown vapor?
Halide ion: Br−\text{Br}^-Br−; role of sulfuric acid: oxidising agent
Halide ion: Br−\text{Br}^-Br−; role of sulfuric acid: reducing agent
Halide ion: I−\text{I}^-I−; role of sulfuric acid: oxidising agent
Halide ion: Cl−\text{Cl}^-Cl−; role of sulfuric acid: acid
106 exam-style questions on Edexcel GCSE Chemistry 7.2 Group 7, covering 7.2.1 Physical properties of the halogens, 7.2.2 Reactions of the halogens, 7.2.3 Relative reactivity and displacement reactions of the halogens, and 7.2.4 Halogen displacement as a redox reaction. Each one has a worked solution and a mark scheme showing where the marks go.