VIDEO 4 – SUPPORTING MATERIALS
Acetylene Production from Calcium Carbide
Summary of the Chemical Reactions
The chemical equations for the reactions involved in this investigation are:
CaC2(s) + 2 H2O(l) → C2H2(g) + Ca(OH)2(aq)
2 C2H2(g) + 5 O2(g) → 4 CO2(g) + 2 H2O(g)
(complete combustion)
3 C2H2(g) + 3 O2(g) → CO2(g) + CO(g) + 4 C(s) + 3 H2O(g)
(incomplete combustion)
Complete combustion occurs when the oxygen supply is plentiful. Incomplete combustion
occurs when the oxygen supply is limited. Please note that the reaction products of incomplete
combustion vary depending on the proportion of oxygen to fuel present. Hence, incomplete
combustion cannot be represented by a single chemical equation. The equation provided above
is only a sample equation of incomplete combustion.
Prior to beginning this investigation teachers are reminded to discuss fire safety procedures with
their students including:
- evacuation procedures;
- location and use of the fire extinguisher;
- potential dangers associated with this activity; and
- the need to carefully follow the instructions and example of the teacher.
Safety Points
• All materials should be transported on a cart with four raised sides.
• The calcium carbide is water-reactive and should be kept in a sealed vial.
• The splint and candle should be extinguished as soon as they are no longer required.
• Safety goggles are required for this investigation.
• Students must also ensure that long hair is tied back, hats removed, and loose clothing is
tucked in or removed.
• Students need to be a safe distance from the mouth of the test tube when blowing air gently
at the flame.
• Air should be blown into the test tube from the side, as opposed to from above.
• You should be the only one to control the lighter and therefore when there is and is not
flame in the classroom