2 - Chemistry of the Elements Flashcards
1
Q
What are periods?
A
- Rows across
- Properties change as you go along
2
Q
What are groups?
A
- Columns going across
- Similar chemical properties because of the electrons on the outer shell
- Gradually change as you go down and the atomic number increases
3
Q
What are metals in the periodic table?
A
The majority (including aluminium)
4
Q
What are non-metals in the periodic table?
A
The minority (including oxygen and boron)
5
Q
Group 0 properties
A
- Noble gases
- All inert
- Full outer shell of electrons
6
Q
Group 1 properties
A
- The alkali metals
- Reactivity increases going down
- All react similarly with water
7
Q
How do group 1 react with water?
A
e.g. sodium + water –> sodium hydroxide + hydrogen
solid + liquid –> aqueous + gas
8
Q
Describe an experiment to show alkali metals reacting with water
A
- Put a small lump in a beaker with water
- Universal indicator shows the colour change (green to blue to purple (alkaline))
- Use a stopwatch to time how long it takes to fizz out
- As you go down the group it will react more vigorously and quicker
9
Q
Describe an experiment to show alkali metals reacting with water
A
- Put a small lump in a beaker with water
- Universal indicator shows the colour change (green to blue to purple (alkaline))
- Use a stopwatch to time how long it takes to fizz out
- As you go down the group it will react more vigorously and quicker
10
Q
Group 7 properties
A
- Halogens
- Colour gets darker as you go down
- Solidify as you go down
- boiling point increases
11
Q
Group 7 properties
A
- Halogens
- Colour gets darker as you go down
- Solidify as you go down
- boiling point increases
- Reactivity decreases (shell with missing electron in further away from nucleus)
12
Q
What happens to hydrogen chloride gases in water?
A
- It dissociates
- The ions split into H+ ions and Cl- ions
- Hydrochloric acid is formed
- This doesn’t happen in methylbenzene because it isn’t acidic
13
Q
What are the state symbols in a halogen displacement reaction?
A
All aqueous
14
Q
What is an oxidising agent?
A
Something in a reaction that accepts electrons and gets reduced (the more reactive element is normally the oxidising agent)
15
Q
What is a reducing agent?
A
Something that loses electrons and gets oxidised (the less reactive element is normally the reducing agent)
16
Q
What is a redox reaction?
A
A reaction where reduction and oxidation occur at the same time
17
Q
What is a redox reaction?
A
A reaction where reduction and oxidation occur at the same time
18
Q
What happens when chlorine water is added to potassium bromide solution
A
- Turns from colourless to orange
-
19
Q
What happens when chlorine water is added to potassium bromide solution
A
- Turns from colourless to orange
- Displacement reaction
- Potassium chloride and bromine is formed
20
Q
What happens when chlorine water is added to potassium iodide solution?
A
- Turns from colourless to brown
- Displacement reaction
- Potassium chloride and iodine is formed
21
Q
What happens when bromine water is added to potassium iodide solution?
A
- Turns from colourless to brown
- Displacement reaction
- Potassium bromide and iodide is formed
22
Q
What does an acid + metal make?
A
Acid + metal –> salt + hydrogen
23
Q
What does a metal + water make?
A
Metal + water –> metal hydroxide + hydrogen
24
Q
What is the reactivity series?
A
Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Hydrogen, Copper, Silver, Gold
25
What is rust?
The corrosion of iron or steel when it meets oxygen (from the air) and water
- It is an oxidation reaction (the iron gains oxygen)
26
What is the symbol equation for rust?
iron + oxygen + water --> hydrated iron(III) oxide
27
What are ways to prevent rusting?
- Barrier methods
| - Sacrificial method
28
What is the barrier method?
- Coating the iron to prevent oxygen/water reacting with it
- Plastic/coating with plastic is often used for big and small structures
- Oiling/greasing is used when moving parts are involved
29
What is the barrier method?
- Coating the iron to prevent oxygen/water reacting with it
- Plastic/coating with plastic is often used for big and small structures
- Oiling/greasing is used when moving parts are involved
30
What is the sacrificial method?
- Using a more reactive metal to corrode instead of iron
- Zinc is often used
- Spraying zinc or putting big blocks bolted to it
31
What is galvanising?
Spraying zinc in sacrificial method
32
How much nitrogen is in the air?
78%
33
How much oxygen is in the atmosphere?
21%
34
How much argon is in the atmosphere?
1%
35
How much carbon dioxide is in the atmosphere?
0.04%
36
What are the main gases in the atmosphere?
Nitrogen, oxygen, argon and carbon dioxide
37
Describe an experiment using copper to show there is oxygen in the air
- Put excess copper in a tube and pass air over it using two syringes
-
38
Describe an experiment using copper to show there is oxygen in the air
- Put excess copper in a tube and pass air over it using two syringes
- Make marks on the syringes so you can see how much O2 is used up
- Heat the copper in the middle and oxygen will be lost
- If you start with 100cm3 of air you will end up with about 80cm3 showing 20% of air must be oxygen
39
Describe an experiment to show oxygen in air using iron or phosphorus
- Iron reacts with air to form rust
- Soak some iron wool with acetic acid (the catalyst) the put the wool in a test tube with your thumb over the end in a beaker of water
- Over time the water level will rise
- This is to take up the space left by oxygen reacting
- To work out the amount lost mark the start and end position of the water
- About 20% oxygen should be used
40
Describe an experiment to make oxygen in a lab
- Through the decomposition of hydrogen peroxide (H2O2)
- Decomposes to make oxygen and water
- Manganese (VI) oxide can be used as a catalyst
- It can be collected over water or in a gas syringe
41
What colour is the magnesium flame in air?
- Bright white flame
- White precipitate
- Will be alkaline when dissolved in water
42
What colour is the carbon flame in air?
- Orangey/yellow flame
- Produces a carbon dioxide gas
- Slightly acidic in water
43
What colour is the sulphur flame in air?
- Pale blue flame
- Produces sulphur dioxide
- Acidic in water
44
Describe an experiment to make carbon dioxide
- Calcium carbonate (marble chips) put in the bottom of a flask with dilute hydrochloric acid
- The dilute HCl reacts with the calcium carbonate to produce calcium chloride, water and CO2 gas
- Can be collected in a gas syringe or a downward delivery
45
When do you use a downward delivery?
When the gas is heavier than air (e.g. CO2, Cl2)
46
When do you use an upward delivery?
When the gas is lighter than air (e.g. H2)
47
When do you use an upward delivery?
When the gas is lighter than air (e.g. H2)
48
Describe an experiment to make carbon dioxide using thermal decomposition
- Heating green copper carbonate
| - Black copper oxide and carbon dioxide gas will be collected
49
When is carbon dioxide used?
- In fizzy drinks
- Reacted with water to make carbonic acid
- Used in fire extinguishers as it is more dense than air so sinks into the flame and stops oxygen getting to it
- Used mainly for putting out electrical fires
50
Why is carbon dioxide a greenhouse gas?
- It absorbs most of the heat that is radiated out into space and radiates it back to earth which warms it up
- Released in deforestation and burning fossil fuels
51
What colour is a lithium flame?
Crimson red
52
What colour is a sodium flame?
Yellow/orange
53
What colour is a potassium flame?
Lilac
54
What colour is a calcium flame?
Brick red
55
How do you do a flame test?
- Clean a platinum wire loop by dipping it in dilute HCl
| - Hold it to the flame
56
What colour is a copper (II) precipitate?
- Blue
| - Cu2+(aq) + 2OH(aq)- --> Cu(OH)2(s)
57
What colour is an iron (II) precipitate?
- Sludgy green
| - Fe2+(aq) + 2OH-(aq) --> Fe(OH)2(s)
58
What colour is an iron (III) precipitate?
- Red/brown
| - Fe3+(aq) + 3OH-(aq) --> Fe(OH)3(s)
59
What is a test for ammonia?
- Damp red litmus paper will turn blue
| - To test for ammonium ions add sodium hydroxide and ammonia gas will be given off
60
What is a test for ammonia?
- Damp red litmus paper will turn blue
- To test for ammonium ions add sodium hydroxide and ammonia gas will be given off
- Strong smell
61
How can you test for carbonates?
- Add dilute HCl
| - Carbon dioxide will be released
62
How can you test for sulphates?
- Sulphate ions produce a white precipitate
- Add dilute HCl
- Add barium chloride solution
- A white precipitate will form
- (The HCl removes any carbonate or sulphite ions)
63
How can you test for halides?
- Add nitric acid
| - Add silver nitrate solution
64
What colour is a silver chloride precipitate?
White
65
What colour is a silver bromide precipitate
Cream
66
What colour is a silver iodide precipitate?
Yellow
67
How can you test for chlorine gas?
Bleaches damp litmus paper
68
How can you test for oxygen?
Relights a glowing splint
69
How can you test for carbon dioxide?
Turns limewater cloudy
70
How can you test for hydrogen?
Makes a 'squeaky pop' with a lightened splint
71
How can you test for water chemically?
- Wet copper(II) sulphate is blue
- If you heat the water off it'll turn white
- Add water it will turn blue again
72
How can you test for water physically?
- Boils at 100*C
| - Freezes at 0*C
