1.42 g of chlorine reacts completely with excess potassium iodide solution.
Cl2+2I−→2Cl−+I2\mathrm{Cl_{2} + 2I^{-} \rightarrow 2Cl^{-} + I_{2}}Cl2+2I−→2Cl−+I2
How many electrons are transferred from iodide ions to chlorine?
(relative atomic mass: Cl = 35.5; Avogadro constant = 6.02 × 1023 per mole)
1.20×10221.20\times10^{22}1.20×1022
2.41×10222.41\times10^{22}2.41×1022
4.82×10224.82\times10^{22}4.82×1022
8.55×10238.55\times10^{23}8.55×1023
41 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.