Chemistry 0620 · IGCSE · Group VII properties

Group VII properties — practice question

This question focuses on iodine and compounds containing iodine.
(a)[4]

Use the kinetic particle model to describe how far apart the molecules are and how the molecules move in: • solid iodine • iodine gas

(b)[1]

Describe how the volume of iodine gas changes as pressure changes.

(c(i))[2]

Fill in the word equation so that it shows the halogen and halide compound that react to make iodine and potassium bromide. [BLANK] + [BLANK] → iodine + potassium bromide

(c(ii))[1]

Explain, in terms of halogen reactivity, why aqueous iodine does not react with aqueous potassium chloride.

(d(i))[2]

Balance the chemical equation for this reaction. $\ldots\text{Na}_2\text{S}_2\text{O}_3 + \text{I}_2 \rightarrow \text{Na}_2\text{S}_4\text{O}_6 + \ldots\text{NaI}$

(d(ii))[1]

Explain how this diagram shows that the reaction is exothermic.

(e)[2]

Describe a test for iodide ions. test Observations

(f)[1]

Predict the product formed at the positive electrode.

Worked solution & mark scheme

This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: solid: particles in contact / close together

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI