Tests for gases
Many acid reactions produce gases which can help identify the mechanisms and products involved.
Oxygen
To test for oxygen a glowing split can be placed in the gas. If the gas is oxygen the splint will relight.
Hydrogen
To test for hydrogen a small sample can be ignited. Hydrogen will make a squeaky pop when lit in air, care needs to be taken with this test as large amounts of hydrogen are very explosive in air.
Hydrogen reacts very quickly with oxygen to form water.
Carbon Dioxide
There are two tests for carbon dioxide. Firstly it will extinguish a flame, however, as any oxygen free gas will also extinguish a flame this is a poor gas test and may result in misidentification.
The best way of testing for Carbon dioxide is to bubble it through lime water. A positive test will result in the lime water turning milky. Lime water turns milky as the Calcium hydroxide (chemical name for limewater) reacts with carbon dioxide to form Calcium Carbonate which is insoluble in water and thus forms a milky white precipitate.
Many acid reactions produce gases which can help identify the mechanisms and products involved.
Oxygen
To test for oxygen a glowing split can be placed in the gas. If the gas is oxygen the splint will relight.
Hydrogen
To test for hydrogen a small sample can be ignited. Hydrogen will make a squeaky pop when lit in air, care needs to be taken with this test as large amounts of hydrogen are very explosive in air.
Hydrogen reacts very quickly with oxygen to form water.
Carbon Dioxide
There are two tests for carbon dioxide. Firstly it will extinguish a flame, however, as any oxygen free gas will also extinguish a flame this is a poor gas test and may result in misidentification.
The best way of testing for Carbon dioxide is to bubble it through lime water. A positive test will result in the lime water turning milky. Lime water turns milky as the Calcium hydroxide (chemical name for limewater) reacts with carbon dioxide to form Calcium Carbonate which is insoluble in water and thus forms a milky white precipitate.