Gases Test Procedures PDF

Here are the detailed descriptions of the tests for oxygen gas: 1. Burning splint test: - Materials needed: Burning wooden splint, test tube containing oxygen sample, gas lighter - Procedure: - Light a wooden splint with a gas lighter to make it burn brightly. - Remove the stopper from a test tube c...

Here are the detailed descriptions of the tests for oxygen gas: 1. Burning splint test: - Materials needed: Burning wooden splint, test tube containing oxygen sample, gas lighter - Procedure: - Light a wooden splint with a gas lighter to make it burn brightly. - Remove the stopper from a test tube containing oxygen sample. - Quickly put the burning splint into the test tube. - Observation: The burning splint continues burning brightly inside the test tube. 2. Glowing splint test: - Materials needed: Glowing (not burning) wooden splint, test tube containing oxygen sample - Procedure: - Light a wooden splint and allow it to glow (not burn) at the tip. - Remove the stopper from a test tube containing oxygen sample. - Quickly put the glowing splint into the test tube. - Observation: The glowing splint relights and burns brightly inside the test tube, indicating the presence of oxygen. In both tests, oxygen supports combustion by allowing the burning/glowing splint to continue burning brightly inside the test tube. This demonstrates oxygen's property of supporting combustion. The glowing splint test is a more sensitive test for oxygen than the burning splint test. Here are the detailed descriptions of the tests for carbon dioxide mentioned in the document: 1. Limewater test: - Materials needed: Limewater solution, test tube containing carbon dioxide sample - Procedure: - Add 2cm3 of limewater into a test tube containing the carbon dioxide sample. - Stopper the test tube and shake it gently. - Observation: The limewater turns milky white, indicating the formation of calcium carbonate precipitate. - Reaction: Carbon dioxide + limewater → calcium carbonate (precipitate) + water - This test shows carbon dioxide reacts with calcium hydroxide in limewater to form calcium carbonate precipitate. 2. Hydrogen carbonate indicator test: - Materials needed: Hydrogen carbonate (bicarbonate) indicator solution, test tube containing carbon dioxide sample - Procedure: - Add 2cm3 of hydrogen carbonate indicator into a test tube containing the carbon dioxide sample. - Stopper the test tube and shake it gently. - Observation: The indicator solution turns red, showing the presence of carbonic acid. - Reaction: Carbon dioxide + water → carbonic acid - The indicator is used to detect the presence of carbonic acid formed when carbon dioxide dissolves in water. The color change from natural to red indicates carbon dioxide is present. Both tests detect carbon dioxide based on its chemical reactions - with limewater and with water to form carbonic acid respectively. The formation of precipitate/color change clearly shows the presence of carbon dioxide. Here are the descriptions of the tests used to identify nitrogen gas: 1. Glowing/Burning Splint Test Materials Needed: - Glowing/burning wooden splint - Test tube containing unknown gas sample Procedure: - Insert the glowing/burning splint into the test tube containing the gas sample. Observation: - The splint's flame will go out immediately. Result: - Nitrogen does not support combustion. The splint will not continue burning in nitrogen gas. 2. Limewater Test Materials Needed: - Limewater solution - Test tube containing gas sample Procedure: - Add limewater to the test tube containing the gas sample. Observation: - The limewater will remain clear with no reaction. Result: - Nitrogen is an inert gas and does not react with limewater. There are no simple chemical tests for nitrogen gas since it is chemically inert. The splint test shows nitrogen does not support combustion, while the limewater test shows nitrogen does not react. A lack of any observable reactions indicates the gas is likely nitrogen. Here are the tests to identify air: 1. Burning/Glowing Splint Test Materials: Burning/glowing wooden splint, test tube containing gas sample Procedure: Insert the burning/glowing splint into the test tube. Observation: The splint will continue burning/glowing. Result: Air supports combustion due to the presence of oxygen. 2. Limewater Test Materials: Limewater solution, test tube containing gas sample Procedure: Add limewater to the test tube. Observation: The limewater will remain clear initially but will become cloudy after some time. Result: Carbon dioxide in air reacts slowly with limewater to form calcium carbonate precipitate. 3. Hydrogen Carbonate Indicator Test Materials: Indicator solution, test tube containing gas sample Procedure: Add indicator solution to the test tube. Observation: The solution will turn faint pink showing presence of carbon dioxide. Result: Carbon dioxide in air reacts with water to form carbonic acid detected by the indicator. Air gives a positive result in all three tests due to the presence of oxygen, nitrogen and carbon dioxide. The splint test shows oxygen supports combustion. The limewater and indicator tests detect carbon dioxide through chemical reactions. This confirms the sample contains normal air.