Criteria you should assess yourself on to be confident in your knowledge of Concept 2: Gas Tests. Vocabulary you must learn to be able to understand a question and answer it confidently. Click this drop-down menu to see the Success Criteria.
Click this drop-down menu to see the list of Vocabulary. Glowing splint test: Test for oxygen gas. Limewater: Solution that turns cloudy when carbon dioxide is bubbled through it. Lit splint test: Test for carbon dioxide gas that uses a splint. Pop test: Test for hydrogen gas.
Oxygen is needed for combustion (burning carbon from the wooden splint). If oxygen is present in a test tube, a GLOWING SPLINT re-ignites when it is held inside that tube and exposed to a high concentration of oxygen.
Hydrogen ignites in air. So if hydrogen is present in the test tube, a lit splint held near the mouth of the test tube will ignite with a squeaky POP!
Carbon dioxide displaces (removes) oxygen from the test tube. If there is no oxygen, a flame cannot keep burning, so the flame will be extinguished.
Carbon dioxide is a colourless gas and LIMEWATER is a solution of calcium hydroxide in water, which is also colourless. The carbon dioxide gas reacts with the limewater and changes it into calcium carbonate, which is not soluble (cannot dissolve) in water and appears as a milky white colour. This University Professor demonstrates what happens when hydrogen and oxygen gases react near a flame. Clear demonstrations of how to test for oxygen and carbon dioxide. Includes the limewater test and tealight candles, which we did not do in class. No sound. Clear demonstration of how to test for oxygen, carbon dioxide, and hydrogen. There's also information on how to test for chlorine gas, but you don't need to know about this.
Many resources found on this website have been copied or adapted from other sources, for the purpose of classroom teaching. If you own any of the intellectual property that I have copied or adapted, and wish for it to be removed from this website, please email |