Chemistry · Ch 13 — Hydrocarbons
Uses of Alkynes
Uses of Alkynes
(1) Acetylene burnt with oxygen in an oxyacetylene torch reaches over 3000°C, making it the standard fuel for welding and cutting steel. (2) It is a key polymer-industry feedstock: hydration (Kucherov's reaction) converts it to acetaldehyde, a route once important industrially; addition of HCl gives vinyl chloride for PVC and, via vinylacetylene and chloroprene, neoprene synthetic rubber; addition of acetic acid gives vinyl acetate for polyvinyl acetate, and of alcohols gives vinyl ethers for polyvinyl ether. (3) Cyclic trimerisation of acetylene over an activated-carbon catalyst gives benzene, an important route to aromatic feedstock. (4) Dilu …
Worked out. Two short completion exercises on alkyne addition chemistry: (i) an alkyne reacting with one mole of H2 over platinum to give the corresponding alkene, which then reacts with a further mole of H2 over platinum to give the alkane; (ii) an alkyne reacting with excess H2 over platinum directly to the saturated alkane. …