Chemistry: 6. Carbon Dioxide
Please remember to photocopy 4 pages onto one sheet by going A3→A4 and using back to back on the photocopier.
OC27 Prepare carbon dioxide (word equation and chemical equation), and show that it does not support combustion
OC28 Carry out simple tests on carbon dioxide involving its reaction with limewater (word equation and chemical equation), and with moist litmus paper
OC29 Investigate the density of carbon dioxide relative to air (qualitative only), and state two uses of carbon dioxide
Preparation of carbon dioxide
CaCO3 + 2HCl → CaCl2 + H2O + CO2
Set up as shown (calcium carbonate is the chemical name for marble chips).
Pour a small volume of limewater into the jar and shake – the limewater will turn milky showing that the gas is carbon dioxide.
Add water to a fresh jar of carbon dioxide and test with blue litmus paper: it turns red demonstrating that it is an acid.
Limewater and carbon dioxide
Ca(OH)2 + CO2 → CaCO3 + H2O
To show that carbon dioxide does not support combustion
Light a wooden splint and insert it into a gas jar of carbon dioxide.
Result: the splint will extinguish showing that carbon dioxide does not support combustion.
Pour the gas over the candle as shown.
Because carbon dioxide is denser than air the gas sinks and extinguishes the candle.
Uses of carbon dioxide
Give the chemical name for marble.
The diagram shows an arrangement of apparatus suitable for the preparation of carbon dioxide gas in a school laboratory.
Name suitable substances X and Y from which carbon dioxide can be made.
Give the formula of a suitable acid.
Name the chemical that turns milky white if carbon dioxide is bubbled through it.
The liquid and solid shown in the diagram react together to produce a gas that turns limewater milky. Name a liquid and a solid that react together in this way.
Carbon dioxide turns limewater milky.
Complete the chemical equation for the reaction of carbon dioxide with limewater.
Ca(OH)2 + CO2 →
If a strip of moist blue litmus paper and a strip of moist red litmus paper are put into a jar of carbon dioxide what effect, if any, does the gas have on them?
Carbon was burned in oxygen and the products tested with pieces of moist red and blue litmus paper.
Give the result of the litmus test described above and make a conclusion based on this result.
The diagram shows a gas jar of carbon dioxide gas being poured onto a lighting candle.
Give two uses of carbon dioxide.
Y: Calcium Carbonate (CaCO3) / limestone / marble chips / chalk
Solid: marble/ calcium carbonate/ CaCO3)/ bread soda/ sodium hydrogen carbonate (sodium bicarbonate)…
Conclusion: The product is acidic.
Other Test Questions
Ca(OH)2 + CO2 +
HCl + CaCO3 + +