Write the equation for how $\text{CaC}_2$ reacts with water.
Draw a ‘dot-and-cross’ diagram for the carbide ion, $\text{C}_2^{2-}$, showing only the outer electrons.
Ethyne is the first member of the alkyne homologous series. Propyne, $\text{C}_3\text{H}_4$, and butyne, $\text{C}_4\text{H}_6$, are the next two members in the series. Deduce the general formula for the alkynes.
Ethyne may be polymerised to form poly(acetylene), a conducting polymer. Suggest why this polymer is able to conduct electricity.
State the empirical formula of poly(acetylene).
By referring to a physical or chemical property, suggest one advantage that a conducting polymer has compared with metals.
Under basic conditions, alkynes can react with carbonyl compounds as shown in reaction 1. The first stage of the mechanism for reaction 1 is the reaction between the alkyne anion and the carbonyl compound. Complete this first stage and draw the intermediate formed. Include every relevant dipole, charge and curly arrow.
Suggest the mechanism name for reaction 1.
An alkyne, Q, and a carbonyl compound, R, react together to make compound P as shown. Using reaction 1, suggest the structures of Q and R.
A series of twelve separate experiments is shown in the table. Complete the table by writing a tick (ၗ) in each box if a reaction occurs, or a cross (ၗ) if no reaction occurs.