how can the presence of carbon dioxide be tested?
Yes All your friends are right!
To test the presence of carbon dioxide gas we pass the carbon dioxide gas into lime water.If the lime water turn milky then carbon dioxide gas is evolved in the chemical reaction. If it does not turn milky then the gas evolved in the chemical reaction is not carbon dioxide.
To test the presence of carbon dioxide gas we pass the carbon dioxide gas into lime water.If the lime water turn milky then carbon dioxide gas is evolved in the chemical reaction. If it does not turn milky then the gas evolved in the chemical reaction is not carbon dioxide.