discussion

DiscussionA. Carbon and Hydrogen O.5g of CuO and 0.1g of sugar was grounded. It was placed into a clean dry test tube. 0.5g of CuO was added. A delivery tube was connected to the test tube containing CuO and sugar and the other tip was dip into a lime water containing test tube, it was then heated. During heating, there was smoke in the test tube with CuO and sugar and the mixture became reddish. On the other hand, the test tube with lime water, also has smoke and a white precipitate is forming. This means that carbon is present. If copper sulphate turns blue due to the formation of CuSO4.5H2O (by water vapor) then the compound contains hydrogen.B. Test for SThe test solution was acidified with a dilute acetic acid and acetate solution. If a black precipitate of PbS, it means S is present but in this experiment, there was no black precipitate. A pale yellow solution was formed when acetic acid and acetate solution was added. Also, instead of black precipitate, a white precipitate was formed, which means that S was not present. White precipitate was formed may be due to the precipitation of the lead (II) ions with the halide ions.C. Test for HalogensTo 1 mL of test solution, HNO3 was added to produce distinct acidity. It was boiled so that to expel any HCN or H2S that may be present. This step was taken to avoid the cyanide ions and sulfide ions cause the error in the halogens test. The sodium halide formed during the sodium fusion test was reacted with the AgNO3 to form the insoluble silver halide as precipitate in the solution. A heavy white precipitate was formed after AgNO3 was added. This indicates the presence of chlorine.D. Test for NTo 1 mL test solution, two drops of FeSO4 was added. The solution turns to yellow after the FeSO4 was added. Two drops of NaOH was then added to produce distinct alkalinity. The solution was then heated to boiling and filtered to remove any FeS. The filtrate was acidified by adding diluted H2SO4 and two drops of FeCl3. The solution became green. There was no precipitate of Prussian blue. This means nitrogen is absent.E. Sodium FusionNa metal was covered with the solid sample. During the coating, you can see the Na metal reacting with the solid sample. There was some bubbles on the surface of Na metal. The Na metal was then placed in a test tube using a tong. It was then heated. It was heated gently to avoid sputtering. The compound was heated until tube is red hot. The tube was then dropped into a beaker containing 10 mL distilled water. The part with fused sample was dropped into the beaker. It was then heated and filtered. The filtrate, which is colorless, will be used as test solution for the elements.F. Test or OxygenThe ferrox test can be used for the detection ofoxygen. The ferrox paper was soaked in three test tube containing 5 drops of hexane, ethanol and a unknown liquid. The hexane was colorless when the ferrox paper was dropped, while ethanol and the unknown liquid became red-purple. When deep-red coloration is observed, oxygen is present. Meanwhile, solutions of non-oxygen compounds remain colorless.