Flame test

THE FLAME TEST

The flame test is a procedure used in chemistry to detect the presence of certain metal ions based on each element’s characteristic emission spectrum.

The test involves introducing a sample of the element or compound to a hot, non-luminous flame, and observing the colour that results. Samples are usually held on a platinum wire cleaned repeatedly with hydrochloric acid to remove traces of previous analytes.

Assessment:

This work can be assessed for Data Collection and Conclusion & Evaluation

Data Collection:

The appearance of compounds, which will be introduced in the flame test:

Recorded colors of the element’s flame:

Data processing and presentation:

Determining the identity of the unknown salt

As I was asked to state the unknown salt on the basis of flame test I checked the colour of the flame. Results:

On the basis of results provided I can state that my unknown salt was sodium chloride (NaCl) because it produced orange flame and it was white with small crystals.

What particles found in the chemicals are responsible for the production of coloured light?

Since all the salts ...

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Recorded colors of the element’s flame:

Data processing and presentation:

Determining the identity of the unknown salt

As I was asked to state the unknown salt on the basis of flame test I checked the colour of the flame. Results:

On the basis of results provided I can state that my unknown salt was sodium chloride (NaCl) because it produced orange flame and it was white with small crystals.

What particles found in the chemicals are responsible for the production of coloured light?

Since all the salts used in the experiment contained the chlorine anion and produced different colours of light, I can state that only metal cations presented in salts are responsible for change of light colour.

Relationship between the colour of light and the amount of energy carried by each photon of light.

Atoms present in the compounds become excited after absorbing the energy from the flame. They become unstable so they have to loose this energy rapidly in order to regain the previous, stable state. Excess of energy is then emitted causing the change of the flame’s colour. Because different atoms absorb and loose different amounts of energy the changes in colour of flame differs.

Why do different chemicals emit different colours of light?

As it has been stated before the amount of energy absorbed and loosed differs from one atom to another, because they have different electronic configuration resulting in different energy levels and emission spectrum.

Why the chemicals have to be heated in the flame first before the coloured light is emitted?

Chemicals have to be heated first to make the atoms jump onto higher energy levels where their emission spectrum is visible for our eyes.

Characteristic colour of flame.

The colours are different because of different emission spectra causing different colours to appear.

Colourful light emissions are applicable to everyday life. Where else you observed colourful light emissions. Are these light emission applications related?

Colourful light emissions can be observed in everyday life in the case of fireworks. As they contain different metal cations, when heated different emission spectra resulting in different colours.

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