Give the characteristic tests for the gases co2,O2,h2,so2
Collect the gas libertaed and pass it through Lime Water. If the lime water turns milky then the collected gas is CO2
If the gas liberated is SO2, there will be a smell of burning matches and the gas will also put out a lit splint.
Light a wooden splint and then blow it off and bring it near the test tube. If the gas liberated is oxygen, the splint will relighten.
And if the collected gas is Hydrogen..it will burn with a 'POP' sound.