Experiment on the Decomposition of a Carbonate
AIM: To carry out a lab experiment to decompose a carbonate using heat, also to carry out appropriate tests for the formation of products as a result of this decomposition.
DISSCUSION: Carbonates are decomposed by heat into the corresponding oxides and carbon dioxide. The temperature of decomposition depends upon the activity of the metal; that is to say, the more active the metal, the more stable is the carbonate. Thus, the carbonates of sodium and potassium are stable at the highest temperature of a Bunsen burner flame, whereas the carbonates of silver and copper are easily decomposed. In this experiment copper (ii) carbonate will be decomposed at a high temperature, forming copper (ii) oxide and carbon dioxide:
CuCO3(s) arrow CuO(s) + CO2(g)
You will test for the formation of copper (ii) oxide and carbon dioxide. Limewater is a sensitive test for CO2, forming a distinctive milky precipitate:
CO2(g) + Ca(OH)2(aq) arrow CaCO3(s) + H2O(l)
APPARUTUS:
* fat Pyrex test tubes x 3
* medium Pyrex test tubes x 2
* holed stopper x 1
* bent glass delivery tube x 1
* rubber tubing x 1
* glass tubing x 1
* retort stand x 2
* Bunsen burner x 1
* Safety glasses x 1
* Copper(ii) carbonate
* Limewater
* Copper(ii) oxide
* 5ml of dilute H2SO4
METHOD:
1) Transfer a small quantity of CuCO3 equivalent to a depth of 1cm into a test tube
2) Clamp the test tube at an angle of 45 degrees and fit a stoppered delivery tube. Immerse the end of the delivery tube into a test tube half-filled with limewater as shown in the diagram.
3) Heat the test tube containing the CuCO3 strongly for a few minutes until a colour change in the carbonate and lime water is observed
4) Record your observations of the changes occurring to the CuCO3 and the limewater
Testing for copper(ii) oxide
5) Allow the black powder (CuO) remaining in the test tube to cool
6) Add 5ml of dilute H2SO4 and warm gently with a Bunsen burner don't boil. Record your observations
7) Transfer small amount
DISSCUSION: Carbonates are decomposed by heat into the corresponding oxides and carbon dioxide. The temperature of decomposition depends upon the activity of the metal; that is to say, the more active the metal, the more stable is the carbonate. Thus, the carbonates of sodium and potassium are stable at the highest temperature of a Bunsen burner flame, whereas the carbonates of silver and copper are easily decomposed. In this experiment copper (ii) carbonate will be decomposed at a high temperature, forming copper (ii) oxide and carbon dioxide:
CuCO3(s) arrow CuO(s) + CO2(g)
You will test for the formation of copper (ii) oxide and carbon dioxide. Limewater is a sensitive test for CO2, forming a distinctive milky precipitate:
CO2(g) + Ca(OH)2(aq) arrow CaCO3(s) + H2O(l)
APPARUTUS:
* fat Pyrex test tubes x 3
* medium Pyrex test tubes x 2
* holed stopper x 1
* bent glass delivery tube x 1
* rubber tubing x 1
* glass tubing x 1
* retort stand x 2
* Bunsen burner x 1
* Safety glasses x 1
* Copper(ii) carbonate
* Limewater
* Copper(ii) oxide
* 5ml of dilute H2SO4
METHOD:
1) Transfer a small quantity of CuCO3 equivalent to a depth of 1cm into a test tube
2) Clamp the test tube at an angle of 45 degrees and fit a stoppered delivery tube. Immerse the end of the delivery tube into a test tube half-filled with limewater as shown in the diagram.
3) Heat the test tube containing the CuCO3 strongly for a few minutes until a colour change in the carbonate and lime water is observed
4) Record your observations of the changes occurring to the CuCO3 and the limewater
Testing for copper(ii) oxide
5) Allow the black powder (CuO) remaining in the test tube to cool
6) Add 5ml of dilute H2SO4 and warm gently with a Bunsen burner don't boil. Record your observations
7) Transfer small amount