C1 Flashcards
What are the key features of solids?
- Strong forces of attraction between particles.
- Particles vibrate, the hotter they become, the more they vibrate.
What are the key features of liquids?
- Forces of attraction weaker than in solids
- Do not keep their shape
What are the key features of gases?
- No attraction between particles, free to move.
- Do not keep shape or volume.
What is it called when a gas turns into a liquid?
Condensing
What is it called when a liquid turns into a solid?
Freezing
What is it called when a solid turns into a liquid?
Melting
What is it called when a liquid turns into a gas?
Boiling
What is an EXOTHERMIC reaction?
A reaction which gives out energy to the surroundings
What is an ENDOTHERMIC reaction?
A reaction which takes in energy from the surroundings
What is activation energy?
Activation energy is the minimum amount of energy required to start a reaction
-Minimum energy required for bonds to break
How can you investigate temperature change? (polystyrene beaker)
-Put a polystyrene cup into a beaker of cotton wool
-Add a first substance to the beaker. Take the temp
-Add a second substance. Take the temp
If the temperature has rised, it is an exothermic reaction.
I the temperature has decreased, it is an endothermic reaction
What reaction is bond breaking?
Endothermic
What reaction is bond forming?
Exothermic
What was phase 1 of the evolution of the atmosphere?
Early atmosphere mostly carbon dioxide with little oxygen.
Volcanic activity released gases like nitrogen, ammonia, methane and water vapour
What was phase 2 of the evolution of the atmosphere?
As the earth cooled, the water vapour condensed to form the oceans. Lots of CO2 was removed from the atmosphere as it was absorbed by the oceans
What was phase 3 of the evolution of the atmosphere?
Plants and algae started to produce oxygen by photosynthesis.
What is the equation for bond energy calculations?
Energy change=energy from reactants-energy from products
What evidence is there of the evolution of the atmosphere?
Ancient rocks contain compounds which form when there is hardly any oxygen.
What is a combustion reaction?
When you burn a hydrocarbon in oxygen and the only products are Water and Carbon dioxide.
What is incomplete combustion?
Incomplete combustion is when there is not enough oxygen.
What are the dangers of incomplete combustion?
Produces carbon monoxide, carbon dioxide, soot etc.
What are the dangers of carbon monoxide?
Can combine with haemoglobin in red blood cells and stop your blood carrying oxygen round your body.
How can sulphur be removed from fuels?
Removing sulfur from fuels uses a lot of energy, releasing Carbon dioxide into the atmosphere.
Why is sulfur dangerous when released from fossil fuels?
- When burnt sulfur is oxidised to form sulfur dioxide
- When this acid is mixed with clouds, it forms sulfuric acid, making acid rain which kills plants and damages buildings.
What are greenhouse gases?
Gases which ac as an insulating layer to the earth, heating it up
What is the greenhouse effect?
- The sun emits electromagnetic radiation
- Some of it passes through the atmosphere and is absorbed by the earth
- The earth emits long wave radiation which warms up the earth when reflected back at the earth
What forms of human activity increase climate change?
Deforestation
Burning fossil fuels
Agriculture
Creating waste
What are the consequences of climate change?
Increased in melting of the polar caps-higher sea levels
Changes in rainfall patterns
More severe storms
What methods are there to reduce the amount of greenhouse gas emissions?
- Renewable sources
- Governments could tax/cap companies on emissions
Why is making greenhouse gas reductions difficult?
- New technologies have unexpected impacts e.g. Release more carbon dioxide.
- Governments may be worried that it could effect the economy
WHow can you test for Chorine?
Chlorine bleaches blue litmus paper white
How can you test for oxygen?
Glowing splint inside a test tube containing oxygen, it will relight.
How can you test for hydrogen?
Squeaky pop test
How can you test for Carbon dioxide?
Bubbling CO2 through calcium hydroxide turns the solution cloudy.
What is a Hydrogen-Oxygen fuel cell? What are the benefits?
A reaction between hydrogen and oxygen which creates water and energy.
- More efficient than power stations.
- Don’t produce pollutants.
How can waste water be made potable?
- It is filtered
- Air is pumped through to increase aerobic bacteria to kill any other impurities
How can sea water be made potable?
Leaving a bowl full of sea water in the warm will allow the water to seperate from the salt
How is chlorination used to make water potable?
Chlorine gas is bubbled through to kill harmful bacteria.
