Chemical Changes essay

The solution from the previous activity, filter paper, Erlenmeyer flask,6. O M HIGHS, stirring rod, 1 0 ml water. The precipitate settled down until the suppurate was clear. Then it was through a filter paper into the Erlenmeyer flask. The precipitate was washed in the beaker using 10 ml of water. The precipitate settled down and was decanted again through the filter paper into the Erlenmeyer flask containing the filtrate. The whole process was repeated until the precipitate is washed four times. The same filter paper was washed with about 1 ml 6. 0 M HIGHS ND then the filtrate was caught in the beaker containing the copper (II) oxide precipitate. Then the solid was dissolved by stirring. More HIGHS was added to dissolve the precipitated completely. The filter paper was washed again with 10 ml water. Then observations were recorded. 4. Reduction of Cue (II) Ions to Metallic Copper Materials used: solution from the previous activity, 1. 5 g Zen dust, 6. 00 M NH, of 0. 100 M Cue(NON)2, Water, 6. 00 M HCI, filter paper, beaker. About 1. 5 g zinc dust was slowly added to the solution in the previous activity with constant stirring. The chemical changes were observed and noted.

It stirred until no reaction is occurring and then more zinc was added to make the solution color less. The completeness of the reaction was tested by adding a few drops of the solution in a test tube containing 1 ml of 6. 00 M NH. This solution was compared to the controlled solution(prepared by adding a drop of 0. 100 M Cue(NON)2 solution and 2 drops of NH to 1 ml water). Observations were noted. The suppurate in the latter step was decanted and discarded and the precipitate was washed in the beaker twice using 10 ml water. The wash water was decanted and discarded after each washing.

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A 10 ml water and a 2 ml 6. 00 M HCI were added to the precipitate slowly. It was stirred until no more change is observed. The precipitate was settled and the suppurate was again decanted and discarded. The precipitate was washed again with 10 ml of water. The wash water was again decanted and discarded. The entire solid (precipitate) was transferred to a beaker to a weighed filter paper. The filter paper was folded and was kept in the locker to be observed in the next meeting. 5. Oxidation of Copper Materials used: solid from the filter paper from the previous activity, evaporating dish, Bunsen burner.

A pinch of the weighed solid (solid from the filter paper from the previous activity) was put into an evaporating dish and was heated directly over a Bunsen burner. Observations were observed and recorded. Ill. Data and Discussions For the first part of the experiment, Cue(NON)2 solution was added with Noah solution and is described with the following equation: Cue(NON)2(as) + 2 Noah(as) +2 Nanny(as) The addition of Noah to the Cue(NON)2 solution produced a blue precipitate since Cue(OH)2 was insoluble in water. Further addition of Noah made the precipitate turn into bluish green.

The acidity of the product was then tested wrought the means of using litmus paper. It was found out that the solution was basic since the blue litmus paper remained blue and the red litmus paper turned to blue. The solution was then boiled for about minutes and the reaction can be described as: Cue(OH)2(s) cue(s) + H2O(I) Heating copper (II) hydroxide lead to the appearance of black precipitate. From the bluish-green color, it changed into a black precipitate. After boiling, the precipitate was then allowed to settle. Noah was added to the suppurate and it was observed that the precipitate turned into a dark brown color.

The elution with added Noah was then heated and it was observed that the solution turned into a chocolate brown color. The precipitate was then allowed to settle until the suppurate was clear. The suppurate was then filtered through the use of filter paper into the Erlenmeyer flask. The filter paper having the copper (II) oxide solid used was washed with 6. MUM HIGHS thus having a reaction of: coo(S) + HIGHS(as) cuscus(as) + H2O(I) It was noted that from the colorless or clear filtrate, it changed into blue. Also, there was a formation of blue precipitate when 6. MUM HIGHS was added.

The Cuscus solution obtained was then added with zinc dust having a chemical equation as follows: Cuscus(as) + Zen(s) Azans(as) + Cue(s) During the addition of more zinc dust, it was observed that there were bubbles. HCI was added to the solution to dissolve the remaining zinc. The precipitate was then after allowed to settle and the suppurate was discarded. The remaining solid was transferred into a filter paper. The filter paper was then air dried and was weighed after. The recorded mass of the filter paper and the solid was 1. Gig. It was also observed that the color of the solid after IR drying was metallic brown.