C12.3 Testing for gases Flashcards
How can hydrogen gas be produced?
Zinc + Sulfuric acid which makes Zin sulfate + hydrogen
How can you collect hydrogen?
Collect hydrogen over water
Collect hydrogen by upward delivery(downward displacement of air)
How can you test for hydrogen gas?
Hold a lighted splint at the open end of the test tube
Positive test for hydrogen - a lighted splints pops
How can you make some oxygen gas?
The decomposition of hydrogen peroxide solution with a little Maganese Iv oxide is added as a catalyst
Which makes water +oxygen
How can you test for oxygen?
Insert a glowing splint ( made by blowing out a lighted splint) in the mouth of the flask
Positive for oxygen gas: A glowing splint relights
How can you make carbon dioxide?
Reacting marble chips and dilute hydrochloric acid
Which makes calcium chloride + water + carbon dioxide
How can you test for CO2?
Bubble the gas collected through limewater (Calcium hydroxide solution)
Positive test for CO2 : limewater turns milky (cloudy white)
How can you make chlorine gas?
Add concentrate HCL to a spatula of moistened potassium manganate VII crystals in a boiling tube held in a rack inside a fume cupboard
A piece of damp blue litmus paper can be held in the mouth of the boiling tube
What is the purpose of a fume cupboard?
Designed to capture and remove air-borne hazardous substances generated during laboratory experiments
How can you test for Chlorine?
Positive for Chlorine gas: a damp blue litmus paper turns white ( as it gets bleached)
Why does hydrogen pop with a lighted splint?
As the hydrogen reacts with oxygen in the air in a small explosion
