Chemical Analysis

To identify a halide, you can do a halide test. By adding silver nitrate and nitric acid to a solution, a colour change will happen identifying the halide that is present. This identifies the negative ion in a compound.

Chlouride = WHITE

Iodide = YELLOW

Bromide = CREAM

For example if you had Sodium Iodide (but you didn't know) you could do a halide test! A yellow precipitate of silver iodide would form and you could identify that idodie was part of the compound.

To test for a carbonate, you add any acid to a solution. This produces a gas (carbon dioxide), which you would collect and add to limewater. If there was a carbonate, the limewter would turn cloudy.

To test for a negative sulphate ion is in a compound, you add dilute hydrochloric acid and barium chlouride to the solution.

If sulphate was present, a white precipitate (barium sulphate) forms.

The flame test is a good way of identifying metals in an ionic compoud. By burning a metal powder, it will burn with a coloured flame. you can identify the metal present according to the colour.

Lithium = CRIMSON

Sodium = YELLOW

Potassium= LILAC

Calcium = RED/ORANGE

Barium = GREEN

You can also identify metal ions if they are in a soulution by adding sodium hydroxide. This forms a metal hydroxide, and these are normally coloured precipitates, so if a coloured precipitate forms you cann tell what metal was present!

Calcium = WHITE

Copper (II) = BLUE

Iron (II) = GREEN

Iron (III) = BROWN

Aluminium = WHITE (but goes clear again in excess NaOH)

Magnesium = WHITE