(a)[2]
Write the symbol equation for this reaction.
(b)[1]
Since calcium carbide is ionic, deduce the formula of the carbide ion.
(c(i))[1]
Explain why ethyne is classified as a hydrocarbon.
(c(ii))[1]
Suggest why ethyne is classed as unsaturated.
(c(iii))[1]
Aqueous bromine reacts with ethyne. Predict the colour change observed in this reaction.
(c(iv))[2]
Draw a dot-and-cross diagram to represent the electronic arrangement in a molecule of ethyne. Show only the outer shell electrons.
(d(i))[2]
Explain, in terms of bond breaking and bond making, why this reaction is exothermic.
(d(ii))[3]
Finish the reaction pathway diagram in Fig. 2.2 for the complete combustion of ethyne. Label the reactants, products, enthalpy change of the reaction $\Delta H$ and activation energy $E_a$.