Chemistry- Electricity and chemical change

?
  • Created by: Kitsune
  • Created on: 04-07-16 05:11
What is electricity?
A stream of electrons
1 of 34
What are insulators?
Substances that don't conduct electricity as they don't have free electrons
2 of 34
Which substances conduct?
Metas and graphite, ionic substances when dissolved or molten
3 of 34
What is electrolysis?
The breakdown of an ionic compound, molten or in an aq. solution, by the passage of electricity
4 of 34
What is electrolyte?
A solution that conducts electricity
5 of 34
Describe the electrolysis of molten lead bromide
At cathode lead ions gain electron and lead forms below cathode. At anode bromide ions lose electrons and bromine gas bubbles off.
6 of 34
What can inert electrodes be made out of?
Carbon, platinum, graphite
7 of 34
Which electrode carries which charge?
Positive anode, negative cathode
8 of 34
What are the rules of electrolysis of molten ionic compounds?
Metal at cathode, non metal at anode
9 of 34
What forms at cathode in an aqueous solution?
Metal or hydrogen
10 of 34
Why can hydrogen form at cathode instead of a metal?
Because if a metal is more reactive than hydrogen it will want to stay as an ion
11 of 34
Why are the products different in electrolysis of molten or dissolved compounds?
In an aq. solution there are ions of water that take part in electrolysis
12 of 34
What forms at anode in an aqueous solution?
A non-metal or oxygen
13 of 34
When does oxygen form at anode instead of a non metal?
When the solution is dilute
14 of 34
At cathode, ions ... electrons
gain
15 of 34
At anode, ions ... electrons
lose
16 of 34
What is brine?
A concentrated solution of sodium chloride, or common salt
17 of 34
What is the word equation for electrolysis of brine?
Sodium chloride + water = chlorine + hydrogen + sodium hydroxide
18 of 34
During the electrolysis of brine, what forms at the cathode?
Hydrogen gas
19 of 34
During the electrolysis of brine, what forms at the anode?
Chlorine gas
20 of 34
What separates the gases formed during electrolysis of brine?
The partially permeable membrane
21 of 34
What takes place at cathode?
Reduction
22 of 34
What takes place at anode?
Oxidation
23 of 34
What are the products of electrolysis of brine?
Chlorine, hydrogen, sodium hydroxide
24 of 34
How are the products of electrolysis of brine dangerous?
Chlorine- poisonous, hydrogen- flammable, sodium hydroxide- corrosive
25 of 34
What are the uses of chlorine?
Medical drugs, paints, bleaches
26 of 34
What are the uses of hydrogen?
Hydrogen peroxide, hydrogen fuel cells, making nylon
27 of 34
What are the uses of sodium hydroxide?
Medical drugs, paper, soap
28 of 34
What are the other 2 uses of electrolysis?
Refining and electroplating
29 of 34
Describe how copper is refined
The electrolyte is dilute copper sulphate solution, copper on anode dissolves, impurities drop to the floor as sludge, a layer of pure copper builds up at cathode
30 of 34
Why do we want copper as pure as possible?
The purer the better it conducts electricity
31 of 34
Define electroplating
Coating a metal with another metal to make it look better or prevent corrosion
32 of 34
Describe electroplating
At cathode place the object to be electroplated, at anode place metal x, the electrolyte is a soluble solution of a compound of metal x
33 of 34
What are the uses of electroplating?
Steel car bumpers coated with chromium, steel cans coated with tin, metal jewellery coated with silver
34 of 34

Other cards in this set

Card 2

Front

What are insulators?

Back

Substances that don't conduct electricity as they don't have free electrons

Card 3

Front

Which substances conduct?

Back

Preview of the front of card 3

Card 4

Front

What is electrolysis?

Back

Preview of the front of card 4

Card 5

Front

What is electrolyte?

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 Electricity and chemical change resources »