I hypothesize that a chemical action has occurred when there is a change in temperature, color. But also when there are bubbles and the evolution of gas. Materials: The materials that were used were Aluminum wire(12 CM), beaker (1 00 ml), hot plate, copper(al) nitrate (1. 0 M), glass stirring rod, gloves, HCI (1. 0 M), lab apron , lab marker, Noah (1. 0 M), ruler, safety goggles, test tube (13 mm x mm) and test tube rack. Procedure: Safety goggles, gloves, and lab apron were put on. (Only the ones who were doing the experiment) ml of water was placed in the mall beaker and heated until boiled.
And the boiled water will be used as the water bath. The lab marker was used to make 3 marks (1 CM apart). 1. 0 M copper (II) nitrate was added to the first mark on the test tube. 1. 0 M sodium hydroxide (Noah) was added up to the second mark on the test tube. The solutions were mixed with the stirring rod. The test tube was put into the water bath. The burner was turned off and the test tube was cooled. 1. 0 M hydrochloric acid (HCI) was added to the third mark on the test tube and was mixed. The 12 CM piece of aluminum was placed in the test tube. The wire was removed from the test tube. Lab station and equipment were cleaned.
Observations: I observed that color change occurred and turned blue when Copper (II) nitrate and sodium hydroxide were stirred. Also precipitate was formed. When the test tube was placed in the water bath color change occurred again and turned black. Also there was a temperature change occurred, then the 2 substances on the test tube separated and the leftovers dissolved. When the aluminum wire was placed in the test tube bubbles were produced. Within 5 min. Copper atoms formed and were the same color as copper but different shape. Analysis: Some causes of chemical changes are combining chemicals and adding energy.
Two ways that energy is involved in chemical change is when you touch the bottom of the beaker to check the temperature. That involves chemical change. Also when we put the aluminum wire; energy was involved to produce the bubbles. Elements that were used or produced were AY, Cue, H2O and the compounds were cue (NON)2, Noah, cue (OH) 2, Quo, HCI, Chuck, and CAB. Aluminum chloride is in the solution and you can recover it by evaporating the water. The color of solutions of copper compounds is copper color. Soluble: Copper (II) nitrate, sodium hydroxide, hydrogen chloride, copper (II) chloride, aluminum chloride.
Insoluble: copper (II) hydroxide, copper (II) oxide, copper metal, aluminum metal. A) sodium nitrate+ copper (II) hydroxide B) copper (II) + water C) copper (II) chloride + water D) copper + aluminum chloride E) hydrogen + aluminum chloride Conclusion: The 4 type of observations that indicate when a chemical change has occurred is formation of a precipitate, color change, formation of a gas, evolution of energy. The type of reactions that I observed n this experiment could be useful in the recycling of copper because copper metal was used in the preparation of the original copper (II) nitrate solution.
After several conversions copper metal was again recovered. Advantages: pure metal is obtained from a compound, and the reaction is done in one vessel. Disadvantages: the reaction takes time and may be expensive and the waste products of recovery may cause pollution. Further Questions: 1) If you recover aluminum chloride, would there be a color change? 2) Why did the substances produce copper atoms? 3) How do you know if evolution of energy has occurred?