What is the test for CO2 gas? Describe the overall reaction that takes place in the instance of a positive result and write its reaction equation.

The gas is passed through a container of Lime-water, if the Lime-water goes cloudy it means that the gas is CO2. The Carbon dioxide reacts with Calcium hydroxide to produce a Calcium carbonate precipitate and water:CO2 + Ca(OH)2 -----> CaCO3 + H2O