How do you distinguish between gases produced in a reaction?

Gases produced in a reaction can be distinguished by their physical properties, chemical reactivity, and through specific tests.

In a chemical reaction, different gases are produced and each gas has unique properties that can be used to identify it. These properties include colour, smell, density, solubility, and reactivity. For instance, chlorine gas is greenish-yellow and has a pungent odour, while oxygen is colourless, odourless, and supports combustion.

Chemical reactivity is another way to distinguish gases. Some gases react with other substances to produce characteristic results. For example, hydrogen gas reacts explosively with oxygen, while carbon dioxide extinguishes a burning splint.

Specific tests can also be used to identify gases. For instance, the 'limewater test' is used to identify carbon dioxide. In this test, if carbon dioxide is bubbled through limewater (a solution of calcium hydroxide), it turns the limewater milky. This is due to the formation of calcium carbonate, a white precipitate. Similarly, the 'glowing splint test' is used for oxygen. In this test, a glowing splint relights in the presence of oxygen.

Another example is the 'pop test' for hydrogen. In this test, a lit splint is brought near the mouth of the test tube containing the gas. If the gas is hydrogen, it burns with a 'pop' sound.

Ammonia can be identified by its characteristic pungent smell and by its reaction with damp red litmus paper, which it turns blue due to its alkaline nature.

In summary, the identification of gases produced in a chemical reaction involves a combination of observing their physical properties, assessing their chemical reactivity, and conducting specific tests. It's important to remember that safety precautions should always be taken when handling gases, as some can be harmful or dangerous.