How can you identify hydrogen, oxygen and carbon dioxide by their chemical properties?
Which one burns in air?
Which one will not burn?
Which one supports rapid burning?
To identify hydrogen, oxygen, and carbon dioxide based on their chemical properties, you can perform various tests and observations:
1. Hydrogen (H2):
- Test for flammability: Hydrogen is highly flammable, so you can ignite a gas sample of hydrogen. It will produce a "pop" sound if present.
- Reaction with oxygen: Hydrogen combines explosively with oxygen to form water. You can observe a vigorous reaction when hydrogen gas is ignited in the presence of oxygen.
- Test with a glowing splint: Hydrogen reacts with oxygen to produce water. Inserting a glowing splint into a gas sample of hydrogen will cause it to extinguish, indicating the presence of hydrogen.
2. Oxygen (O2):
- Test for reactivity: Oxygen is highly reactive and supports combustion. You can place a glowing splint into a gas sample of oxygen, and it will cause the splint to reignite.
- Reaction with metals: Oxygen reacts with many metals to form metal oxides. For example, if you heat a metal, such as steel wool, in the presence of oxygen, it will form iron oxide (rust).
- Test with a reagent: You can use a reagent like potassium permanganate (KMnO4) or hydrogen peroxide (H2O2). Oxygen readily oxidizes these substances, causing a change in color or release of gas.
3. Carbon Dioxide (CO2):
- Test for carbonation: Carbon dioxide dissolves in water to form carbonic acid, which gives a slightly acidic taste. Therefore, bubbling carbon dioxide through a solution will make it slightly acidic.
- Reaction with limewater: Carbon dioxide reacts with calcium hydroxide (limewater) to form a white precipitate of calcium carbonate. If you pass carbon dioxide gas through limewater, the limewater will turn milky.
- Test with a burning splint: Carbon dioxide is a non-combustible gas and does not support combustion. If you try to ignite a gas sample of carbon dioxide, the burning splint will be extinguished.
Please note that these tests are just a few examples, and there may be other specific tests or methods based on the situation or equipment available. It's always important to consider safety precautions and consult appropriate scientific resources before conducting chemical experiments.