concept card - air we need oxygen to breathe so i think air is oxygen i think air is a mixture of...
TRANSCRIPT
Concept Card - Air
We need Oxygen to breathe so I think Air is Oxygen
I think Air is a mixture of gases
THINK, PAIR SHARE ….What do you think?
Gases in the Air
Q4. Draw a bar graph to show the composition of gases in the air.
Q1. What % of the air is oxygen?
Q2. What % of the air is nitrogen?Q3. What % of the air is carbon dioxide?
Testing for Gases
Collect a test tube and add a tiny amount of MnO2 and then 5 ml of H2O2. O2 is produced.
Have a glowing splint near the mouth of the test tube and remove the stopper.
Carefully place the glowing splint inside the tube, without touching the test tube sides.
Oxygen Gas
What happened to the glowing splint?
Canon Fire
Your teacher will demonstrate an experiment which shows howoxygen increases the rate of burning.
Ethanol and hydrogen peroxide are placed in an evaporatingbasin and set alight. Potassium permanganate is thrown onto theflames. Everyone must be at a safe distance behind the safety screen as the mixture will spit out.
Testing for Gases
Hydrogen Gas
You are now going to make hydrogen gas.
• Place 10 cm3 of Nitric Acid in a test tube.
• Add a few pieces of magnesium shavings.
• Carefully place a burning splint over the mouth of the test tube.
What happened to the burning splint?
zinc
Hydrogen Rocket
A bottle containing hydrogen and oxygen gas is set up
As shown below:
A burning splint, on the end of a metre stick is placed directly under the mouth of the bottle. All pupils should be at the back of the room. Ensure that the bottle is upright and not tilted towards the pupils at the back of the room.
Testing for Gases
Carbon Dioxide GasYou are now going to make carbon dioxide gas. Set up the apparatus shown below. Add 10 cm3 of acid to theconical flask and add chalk chips. The carbon dioxide Produced will be bubbled through the lime water.
acid + marble chips
What happened to the lime water?
Nitric Acid + Chalk Lime water
Carbon Dioxide Gas
Lake Nyos Disaster
Nyos is a deep lake high on the flank of an inactive
Volcano in Cameroon. A pocket of magma lies beneath
the lake and leaks carbon dioxide into water. On August
21, 1986 Nyos emitted a large cloud of CO2, which
suffocated 1,700 people and 3,500 livestock in nearby
villages.
Lake Nyos Demonstration
Sodium hydrogen carbonate is added to Nitric Acid in a large bottle. When they react together, carbon dioxide gas is produced.
Carbon dioxide is heavier than air and will stay in the bottle. Wait a few minutes until the reaction is complete. Pour the carbon dioxide into the container. The candle lowest down should go out first. This demonstrates that carbon dioxide is more dense than air.
Testing for Gases - Summary
Copy and complete the following sentences in your jotter.
The test for oxygen gas is that it ________________ a glowing splint.
The test for hydrogen is that it “_______” with a burning splint.
The test for carbon dioxide is that it turns limewater from
___________ to ____________.
Ring of Fire
Your teacher may let you try the ring of fire for Properties and Usesof Substances.
Pupils can be placed in a ring. Each pupil should be given a cardwhich has a question on the top and an answer on the bottom.The first pupil should read out their question and the pupil with thecorrect answer should shout it out and also read out their question. This continues until all the questions have been answered.
http://www.youtube.com/watch?v=0lhf9U5Wf3Q