A gaseous mixture of CO2 and SO2 was to be identified in a laboratory. Mr. X and Mr. Y performed the experiments as shown in the figure above with common reagents but at different stages.
Mr. Y: Both CO2 andSO2 react with Ca(OH)2 and lime water turns milky. No effect on K2Cr2O7.
Mr. X : SO2 turns K2Cr2O7 green and CO2 does not react at this stage.
CO2 reacts at stage II with Ca(OH)2 and it turns milky.