Tests For Anions
Task 3:
Tests for Anions: An Anion is an atom which is negatively charged therefore indicating a larger amount of electrons than proteins. Overall the tests for anions were mainly conclusive however 6 out of 8 of the anions we were testing for could only be determined from one specific result for example if a black precipitate formed following the tests the substance is therefore a sulphide however the same result would also show the presence of carbonate and hydrogen carbonate this therefore means that it is difficult to distinguish between the two and therefore further tests would need to be carried out this test enables you to distinguish clearly between the two and includes adding a drop of phenolphthalein to the unknown sample therefore …show more content…
Overall the tests for conclusive however 2 out of the 9 tests produced results that were inconclusive and therefore three cations were identifiable. When a white precipitate forms as more sodium hydroxide was added to the unknown substance the possible cations include: Aluminium, Lead (II) or Zinc. Furthermore if a white precipitate forms that does not dissolve as more ammonia solution is added it could mean the cation could be Aluminium, Lead (II) or Magnesium. This therefore means that further tests would need to be carried out in order to identify the aluminium. Following the Cation tests we found that sample C was copper as the addition of dilute sodium hydroxide solution formed a pale blue precipitate which didn’t dissolve as more sodium hydroxide was added. Ammonia solution was then added to the compound and the pale blue precipitate changes to a deep blue solution. This indicated that copper (II) was present. Additionally within the cation test, sample A was identified as zinc as when we added dilute sodium hydroxide solution to the sample a white precipitate should form which dissolves as more sodium hydroxide is added. Then you need to add dilute ammonia solution to the compound and a white precipitate should dissolve as more ammonia solution is added. This therefore shows us that Zinc is present within the …show more content…
However it is often difficult to identify the difference between the colours presented within the flame. The flame test was carried on sample B as the liquid tests didn’t give the results required for a 100% conclusive result therefore a flame test was carried out using a solid compound which when placed within the flame gave of an orange coloured flame consequently indicating the presence of sodium.
Tests for Gases: Overall the tests were conclusive with each of the three tests producing individual results and consequently representing individual gases for example bubbling gas through limewater turns it cloudy and therefore represents the presence of carbon dioxide, the presence of oxygen relights the blown out splint and finally the presence of hydrogen creates a popping sound when placed into the chosen sample
Tests for Anions: An Anion is an atom which is negatively charged therefore indicating a larger amount of electrons than proteins. Overall the tests for anions were mainly conclusive however 6 out of 8 of the anions we were testing for could only be determined from one specific result for example if a black precipitate formed following the tests the substance is therefore a sulphide however the same result would also show the presence of carbonate and hydrogen carbonate this therefore means that it is difficult to distinguish between the two and therefore further tests would need to be carried out this test enables you to distinguish clearly between the two and includes adding a drop of phenolphthalein to the unknown sample therefore …show more content…
Overall the tests for conclusive however 2 out of the 9 tests produced results that were inconclusive and therefore three cations were identifiable. When a white precipitate forms as more sodium hydroxide was added to the unknown substance the possible cations include: Aluminium, Lead (II) or Zinc. Furthermore if a white precipitate forms that does not dissolve as more ammonia solution is added it could mean the cation could be Aluminium, Lead (II) or Magnesium. This therefore means that further tests would need to be carried out in order to identify the aluminium. Following the Cation tests we found that sample C was copper as the addition of dilute sodium hydroxide solution formed a pale blue precipitate which didn’t dissolve as more sodium hydroxide was added. Ammonia solution was then added to the compound and the pale blue precipitate changes to a deep blue solution. This indicated that copper (II) was present. Additionally within the cation test, sample A was identified as zinc as when we added dilute sodium hydroxide solution to the sample a white precipitate should form which dissolves as more sodium hydroxide is added. Then you need to add dilute ammonia solution to the compound and a white precipitate should dissolve as more ammonia solution is added. This therefore shows us that Zinc is present within the …show more content…
However it is often difficult to identify the difference between the colours presented within the flame. The flame test was carried on sample B as the liquid tests didn’t give the results required for a 100% conclusive result therefore a flame test was carried out using a solid compound which when placed within the flame gave of an orange coloured flame consequently indicating the presence of sodium.
Tests for Gases: Overall the tests were conclusive with each of the three tests producing individual results and consequently representing individual gases for example bubbling gas through limewater turns it cloudy and therefore represents the presence of carbon dioxide, the presence of oxygen relights the blown out splint and finally the presence of hydrogen creates a popping sound when placed into the chosen sample