Pentanol is manufactured by reacting pentene, C5H10\text{C}_5\text{H}_{10}C5H10, with steam. The only organic compounds that may be present are pentene and pentanol. Pentanol does not react with bromine water.
A technician tests samples taken before and after purification.
| Sample tested | Observation when orange bromine water is added |
|---|---|
| Reaction mixture before purification | The bromine water turns colourless |
| Pentanol after purification | The bromine water stays orange |
Explain what the observations show about the organic compounds in the two samples.
Give the molecular formula of the organic product formed when pentene reacts with bromine, Br2\text{Br}_2Br2.