Organic Analysis

Acidified potassium dichromate. Turns from orange to green.

No visible change. They aren’t oxidised

Tollens reagent and Fehling’s solution.

Add it to the solution being tested. Warm gently. A silver mirror will form if positive. If not, solution remains colourless.

Add it to the solution being tested. Heat. A brick red precipitate will form if positive. If not, solution remains blue

Use bromine water to test for unsaturated hydrocarbons. It changes from orange/brown to colourless if a carbon-carbon double bond is present. If not, no change is observed.

React the compound with sodium carbonate. CO2 is produced. Collect the gas and bubble through limewater. Solution will turn cloudy if the gas is CO2.

Identifying compounds and determining their molecular formula.

It is a more sensitive form of mass spectrometry. It allows the Mr of a substance to be determined to several decimal places.

Uses infrared radiation to determine the functional groups present in organic compounds. The infrared radiation is passed through a sample where the different types of bonds absorb the radiation in different amounts. The varying amounts of absorbance are measured and recorded to allow functional groups to be identified.

Allows molecules to be identified. On the right hand side of every infrared spectrum before 1500.

It causes heat to be trapped within the Earth’s atmosphere. However when chemicals such as CFCs are released into the atmosphere from human activity, the heating effect is enhanced leading to global warming.