OCR 21st century science C5

HideShow resource information
What is the atmosphere made up of?
Elements like Oxygen and Compounds like Carbon Dioxide.
1 of 42
What is the composition of the atmosphere?
78% nitrogen, 21% oxygen, 1% argon and 0.04% carbon dioxide.
2 of 42
What are the molecular substance's boiling and melting points?
Low.
3 of 42
What are molecular substances like?
They are usually small molecules with very strong intramolecular covalent bonds with weak intermolecular forces and they don't conduct electricity.
4 of 42
What is the hydrosphere?
The hydrosphere is the Earth's oceans, seas, lakes and rivers.
5 of 42
What does the hydrosphere contain?
It contains compounds dissolved in water and many of these are ionic compounds called salts.
6 of 42
What are ionic compounds made of?
They are made up of charged particles called ions, and ions with opposite charges are strongly attracted to each other causing a giant lattice of ions with very strong ionic bonds.
7 of 42
When can ionic compounds conduct electricity?
When they are dissolved the free ions can move in the solution and can carry an electric current which is similar to when they melt.
8 of 42
When can ionic compounds not conduct electricity?
When they are solid the ions aren't free to move so no electric current can pass through.
9 of 42
What colour does sodium give off in a flame test?
Orange/Yellow
10 of 42
What colour does potassium give off in a flame test?
Violet
11 of 42
What colour does calcium give off in a flame test?
Brick-red
12 of 42
What colour does copper give off in a flame test?
Blue-green
13 of 42
What is a precipitation reaction?
When two solutions react to form an insoluble solid compound called a precipitate?
14 of 42
How can you form a precipitate with metal solutions?
Add sodium hydroxide to a solution of the metal.
15 of 42
What colour precipitate do you get when you react sodium hydroxide to a solution of Calcium?
White
16 of 42
What colour precipitate do you get when you react sodium hydroxide to a solution of Copper (II)?
Blue
17 of 42
What colour precipitate do you get when you react sodium hydroxide to a solution of Iron (II)?
Green
18 of 42
What colour precipitate do you get when you react sodium hydroxide to a solution of Iron (III)?
Reddish Brown
19 of 42
What colour precipitate do you get when you react sodium hydroxide to a solution of Zinc?
White at first but then redissolves in excess NaOH to form a colourless solution.
20 of 42
How can you detect carbonates?
By adding HCL carbonates will fizz as they give off Carbon Dioxide and you can also use limewater as CO2 turns limewater cloudy.
21 of 42
How can you test for sulfates?
Add dilute HCL followed by barium chloride and a white precipitate of barium sulfate means the original compound was a sulfate.
22 of 42
What is the HCL for?
To get rid of carbonates so the results are confused.
23 of 42
How can you test for Halides?
Add dilute nitric acid followed by a silver nitrate solution.
24 of 42
What colour precipitate does chloride give off?
White precipitate of silver chloride.
25 of 42
What colour precipitate does bromide give off?
Cream precipitate of silver bromide.
26 of 42
What colour precipitate does iodide give off?
Yellow precipitate of silver iodide.
27 of 42
What is the lithosphere and what are the three main elements?
The lithosphere is the Earth's crust and the mantle below it mainly consisting of oxygen, silicon and aluminium.
28 of 42
What two types of giant covalent structure are made of carbon?
Diamond and Graphite.
29 of 42
What are the properties of Diamond?
The carbon atoms each form four covalent bonds in a very rigid structure, making it very hard with a high boiling point, no electrical conductivity and it is insoluble.
30 of 42
What are the properties of graphite?
Each carbon atom only forms three carbon atoms and is arranged in sheets which can rub off plus it conducts electricity and still has a high melting point.
31 of 42
What form does silicon and oxygen mainly exist as in the crust?
Silicon dioxide which is sand and it has a similar structure to diamond and similar properties like, high melting point and lack of electrical conductivity.
32 of 42
What are metal ores and minerals?
Minerals are just solid elements and compounds and metal ores are rocks that contain minerals from which the metals can be extracted.
33 of 42
What is reduction and oxidisation?
Reduction is when, in the carbon displacement reactions, metal oxide loses it's oxygen and when the carbon gains oxygen it is oxidised.
34 of 42
What is electrolysis?
Electrolysis is the splitting up of a substance using electricity.
35 of 42
What is required for electrolysis?
It needs a liquid to conduct elec called the electrolyte and are usually free ions dissolved in water.
36 of 42
How does electrolysis of Aluminium Oxide take place?
Bauxite is made molten so it'll conduct elec. The positive Al3+ ions are attracted to the cathode where they become molten Aluminum. The negative O2 ions are attracted to the annode where they lose 4 electrons and become O2.
37 of 42
What are the formulas for electrolysis?
Al(3+) + 3e(-) --> Al / 20(2)- --> O(2) + 4e(-) / 2Al(2)O(3) --> 4Al + 3O(2)
38 of 42
What are the properties of Metals?
The positively charged metal ions are held together in a sea of free electrons. They are good conductors, are strong and malleable and have high melting and boiling points due to strong metallic bonds.
39 of 42
What are the positive effects of ore mining?
They provide useful products. It provides jobs and brings in money which allows for improvement of transport and health services.
40 of 42
What are the negative effects of ore mining?
They are finite resources. It is bad for the environment and uses loads of energy. It scars the environment, destroys habitats and creates noise, dust and pollution due to increased traffic. Deep mine shafts are also dangerous.
41 of 42
Why is recycling metals important?
Extraction requires energy which comes from finite fossil fuels so recycling saves money, the negative effects of fossil fuels and conserves resources without landfill space being taken up.
42 of 42

Other cards in this set

Card 2

Front

What is the composition of the atmosphere?

Back

78% nitrogen, 21% oxygen, 1% argon and 0.04% carbon dioxide.

Card 3

Front

What are the molecular substance's boiling and melting points?

Back

Preview of the front of card 3

Card 4

Front

What are molecular substances like?

Back

Preview of the front of card 4

Card 5

Front

What is the hydrosphere?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Chemicals Of the Natural Environment resources »