(a)[3]
Explain these observations in terms of the kinetic particle model.
(b(i))[1]
What does the symbol $\rightleftharpoons$ mean?
(b(ii))[2]
Describe how anhydrous cobalt(II) chloride changes colour when water is added.
(c)[1]
Deduce the molecular formula of this compound, indicating how many cobalt, carbon and oxygen atoms it contains.
(d)[2]
Use this information to arrange the metals by reactivity. Start with the least reactive metal.
(e)[2]
Describe three ways in which cobalt's properties are different from those of lithium.
(f)[1]
Balance the chemical equation for this reaction. $\ldots\text{CoO} + \text{O}_2 \rightarrow 2\text{Co}_3\text{O}_4$
(g)[1]
How does this equation demonstrate that $\text{Co}_3\text{O}_4$ is reduced?