Extract copper from copper oxide by reduction using butane gas
Hypothesis
The butane gas will reduce the copper oxide and leave behind pure copper. This will allow us to find the empirical formula of the copper oxide as well as the masses of oxygen and copper
Variables
Dependant variable
The dependant variable will be the reduction of the copper oxide which will be calculated at different temperatures.
Independent variable
The independent variable here would be the temperature at which the copper oxide is heated.
Controlled variables
The mass of copper oxide used in the test tube
The mass of the test tube
Apparatus
1 test tube with a small opening towards the bottom
1 Bunsen burner
1 Electric Balance
Safety goggles
Constant supply of butane gas
5 grams of the copper oxide
Heat proof mat
Rubber bung
Tube connecting test tube to gas supply
Retort stand
Procedure
Weigh the test tube and record its mass
Add 0.8 grams of copper oxide to the test tube and weigh it and record its mass
Attach a tube connecting the test tube to the gas supply using a rubber bung to prevent the gas from escaping
Suspend the tube using a retort stand
Turn on gas supply into the test tube
Light the small opening at the end of the tube to prevent butane gas from escaping
Place the bunsen burner on the heat proof mat and light it. Place it under the test tube
Record any color changes to the copper oxide
After 7 minutes, turn off the burner and measure the mass of the tube and record it
Repeat until mass of the test tube remains constant after heating
Mass of test tube: 28.10g
Mass of test tube + copper oxide: 28.90g
Observations:
First heating: color of copper oxide turns from black to dark brown to reddish brown
Second heating: color of copper oxide turns from reddish brown to lighter brown
Mass after trial 1: 28.83g
Mass after trial 2: 28.83g
Mass after trial 3: