Copper(I) oxide
Harmful
Dangerous for the environment
H
N
Cuprous oxide Cu
2
O
R22: Harmful if swallowed. R50: Very toxic to aquatic organisms. R53: May cause long-term adverse effects in the aquatic environment.
Dangerous with: ALUMINIUM, MAGNESIUM: Explosive mixtures are formed.
Store: GIn Disposal: W1, W5
W5: React no more than 24 g in 1 litre of warm 1 mol dm
-3
ethanoic acid before pouring the solution and the fine copper precipitate down a foul-water drain. This disposal procedure should be kept to a minimum.
Copper(II) oxide
Harmful
Dangerous for the environment
H
N
Cupric oxide CuO
R22: Harmful if swallowed. R50: Very toxic to aquatic organisms. R53: May cause long-term adverse effects in the aquatic environment.
Dangerous with: ALUMINIUM, MAGNESIUM: Explosive mixtures are formed.
Store: GIn Disposal: W1, W5
W5: React no more than 24 g in 1 litre of warm 1 mol dm
-3
ethanoic acid before pouring down a foul-water drain. This procedure should be kept to a minimum.
Copper(II) carbonate hydroxide Basic copper carbonate; cupric carbonate; malachite
Harmful H R22: Harmful if swallowed.
Store: GIn
CuCO
3
.Cu(OH)
2
Disposal: W1, W5
W5: React no more than 60 g in 1 litre of warm 1 mol dm
-3
ethanoic acid before pouring down a foul-water drain. This procedure should be kept to a minimum.
Copper metal ; Cu
Copper(II) sulfide ; copper pyrites; CuS
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard .
Low hazard Store:
GIn
Disposal:
W2, W8
© CLEAPSS 2007

Activity
Heating carbonate or sulfide ores
Copper(I) oxide preparation
Reduction of the oxide(II) using carbon (crucible)
Reduction of the oxide(II) using carbon (blowpipe)
Reduction of the oxide(II) using methane
Reduction of the oxide(II) with zinc powder
Reduction of the oxide(II) using hydrogen
Reduction of the oxide(II) using magnesium
User
Y7
Y7
Y9
Y9
Y9
Y9
Control measures
Wear eye protection.
Avoid raising dust if using powders.
Wear eye protection.
Wear eye protection.
Ventilate the room well.
Wear eye protection.
Ventilate the room well.
Tie back long hair.
Wear eye protection.
Tie back long hair.
Teacher should supervise the lighting of methane from the combustion tube.
Wear eye protection.
TT Wear goggles or a face shield.
Use safety screens.
TT Wear goggles or a face shield.
Use safety screens.
Do not go back to a seeminglyfailed reaction.
Experimental points
Rocks can spit when heated, so use small amounts, eg, 1 cm
3
in volume. Copper pyrites will produce sulfur dioxide (
TOXIC
) when heated.
Hot Benedict's solution reacts with glucose to form the red precipitate of copper(I) oxide. Avoid Fehling’s solution which is more hazardous.
To observe copper, lift the hot crucible with suitable tongs and pour the contents into cold water; grains of copper will be seen. A bottle-top, with the plastic insert removed, can be used instead of a crucible and, when hot, this can be dropped directly into cold water.
To reduce the amount of copper(II) oxide blown into the air, mix it with a little water and place the paste on the carbon block. Rubber tubing can be connected to the blowpipe; this keeps the face away from the flame. Disinfect rubber tubing in sodium chlorate(I) ( Milton ) after use.
See Hazcard 21.
Methane is passed over hot copper(II) oxide. The gas should not be lit until 10 seconds have passed once the natural gas has been turned on, to allow all the air to be flushed out. When the reaction is complete, keep the gas passing through the apparatus until the reaction vessel has reached room temperature. The flame burning at the exit of the combustion tube should be about 5 cm high. See Handbook 13.3.
Mix no more than 1 g of zinc powder with 1 g of copper(II) oxide on heat-resistant paper (see L195, Safer Chemicals, Safer Procedures ) or on a prepared bottle top (remove the plastic insert).
Large-scale demonstrations have been known to explode. There is a small-scale version in Guide L195, Safer Chemicals, Safer Reactions and a commercial kit available. See Hazcard 48.
See Handbook 13.4. There can be a considerable delay before the violent reaction takes place. If the reaction fails to ignite; turn the gas off using the emergency switch or isolation valve.
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard .
© CLEAPSS 2007