Determine The Identity Of Metals Essay, Research Paper

Experiments to determine the identity of metals by examining the colour of flame when samples of that metal are heated.

The aim of this experiment was to find out whether different metals had different reactions when subjected to the flame of the Bunsen burner. This might then allow the classification and identification of certain metals if they have their own reactions, which will be different coloured flames for this experiment. It was hard for me to predict what would occur during the experiment but I was able to write a hypothesis. I thought that each metal could have been different colours such as oranges, blues and greens.

Equipment:

* Paddle Pop Stick (spatula)

* Bunsen Burner

* Evaporating Basins

* Different Salts

* Hydrochloric Acid – 2 Molar (HCI)

* Lab Coats & Safety Glasses

Method:

Lab coats and safety glasses were worn for protection and safety reasons before the experiment was started. All equipment was collected, the Bunsen was ignited

and a small portion of Sodium Carbonate was placed in a evaporating basin using a paddle pop stick. The Bunsen burner was then moved so that the flame was directly applied to the salt and the resulting flame colour was recorded. This process was repeated with Potassium, Copper, Lithium, Strontium and Lead Carbonate as well as Colbolt and Manganese Dioxide. All of the flame colours were recorded for later use in the results. Then a different process had used to achieve a true colour flame for Aluminium, Zinc, Iron, Lead, Silver, Tin, Nickel, Calcium, Barium. The process was like the first however before heating, a small drop had to plced on the salt as these had no carbon atoms unlike the other group of salts. All of the evaporating dishes were then washed thoroughly after the end of this experiment.

Results:

Name of Salt or Metal

Flame Colour

Sodium Carbonate (Na2CO3)

Orange / Yellow

Potassium Carbonate (K2CO3)

White / Yellow / Blue

Copper Carbonate (CuCO3)

Green

Lithium Carbonate (Li2CO3)

Green with Red Sparks

Strontium Carbonate (SCO3)

Crimson

Manganese Dioxide (MgCo2)

Blue / Orange

Colbolt

White Sparks

Tin Pieces (Sn)

Blue

Lead Carbonate (PbOC3)

Green

Nickel (Ni)

Orange / Green

Calcium (Ca)

Brick Red

Potassium (K)

Lilac

Lithium (Li)

Deep Red

Barium (Ba)

Apple Green

Aluminium (Al)

Zinc (Zn)

Iron (Fe)

Lead (Pb)

Silver (Ag)

Unable to distinguish with flame test.

Must precipitate in alkali.

Conclusion:

After looking at the result of this experiment it was clear that some of the evaporative dishes weren’t cleaned thoroughly. This was because with some of the samples, two flames were noticed such as a green and a red one together. This problem though only occurred on some of the substances while with most of them the group was able to get a single colour instead of the undecided flame.

My hypothesises was mostly correct however I have now learnt that there is such thing as red flame. I also need to change my hypotheses because every substance had a general colour such as green, blue or red. Instead many had more specific colours such as crimson and lilac. After researching why certain substances react to make different colour flames I found out that the heat from the flame affects the electrons in each atom of the substance. When this happens there is a reaction and the energy is turned into visible light but when the flame is removed, the atoms regained their original state. I understand that the colour of the flame really tells how much energy is available to each atom and how much is being used. This basically means that the flame colour distinguishes the atomic structure and the wavelengths of Electromagnetic Radiation (visible colour is apart of this) given off by the substance. I believe the experiment does not need to be done again because the results were fairly accurate however they weren’t as good as I would have expected them to be.