Summer assessment 3 Flashcards
(78 cards)
1
Q
what are ions?
A
charged particles
2
Q
What is ionic bonding between?
A
a metal and non-metal
3
Q
What is ionic bonding?
A
oppositely charged ions are strongly attracted to one another by electrostatic attrations
4
Q
What does ionic bonding form?
A
giant ionic structure
5
Q
Describe giant ionic structure?
A
- ions held together by closely packed 3D lattice arrangement
- strong electrostatic attraction
- high melt + boiling point
- not electrical conductors when solid, only when dissolve in water or melt them
6
Q
Definition of covalent bond?
A
strong electrostatic attraction between negatively charged shared electrons and the positively changed nuclei of the atoms involved
7
Q
Describe simple molecular structures?
A
- very strong covalent bond
- weak intermolecular forces of attraction between molecules
- low melting and boiling point
8
Q
Describe giant covalent structures?
A
- strong covalent bond
- high melting and boiling
- dont conduct electricity
- insoluble in water
9
Q
Describe diamond?
A
- network of carbon atoms with four covalent bonds
- strong covalent bonds
- high melting point
- hard rigid lattice structure
- doesnt conduct
10
Q
Describe graphite?
A
- each carbon forms three covalent bonds
- layers of carbon atoms with weak intermolecular forces which can slide over each other making it slippery and soft
- high melt and boil
- one delocalised electron and can conduct electricity
11
Q
Describe C60 fullerene?
A
- hollow sphere with 60 carbon atoms
- intermolecular foces which can slide over each other - soft
- one delcocalised but cant move molecules so poor conductor
12
Q
What are alkanes?
A
saturated hydrocarbons
13
Q
What are hydrocarbons?
A
chains of carbon and hydrogen atoms
14
Q
alkanes general formula?
A
CnH2n+2
15
Q
name the first five alkanes?
A
methane ethane propane butane pentane
16
Q
WHat do alkanes burn in?
A
combustion reactions
17
Q
What does complete combustion of alkane make?
A
carbon dioxide + water
18
Q
What can alkanes react with? to form?
A
halogens to make haloalkanes
19
Q
what is needed for the substitution reaction?
A
UV light
20
Q
Methane + bromine =?
A
bromomethane + hydrogen bromide
21
Q
What is electric current?
A
flow of electrons or ions
22
Q
What charge do electrons have?
A
negative
23
Q
What happens when electrons or ions move?
A
they cause the material to conduct electricity
24
Q
When do ionic compounds conduct electricity?
A
when molten or in a solution ( ions are separate and c an move in the solution)
25
How are metals held together?
by metallic bonding
26
Describe metallic bonding?
electrostatic attraction between the positive ions and the electrons
27
What are metals good conductors of?
electricity and heat
28
How are most metals malleable?
layers of ions in a metal can slide over each other
29
percentage yeild?
actual yield/ theoretical yeild x100
30
concentration?
moles/ volume
31
volume=?
moles x 24
32
which three metals have properties in commen?
iron, aluminium and copper
33
What are the general properties of iron, aluminium and copper?
- dense and lustrous
- high melting points
- high tensile strength, strong and hard to break
- malleable
- good electrical and heat conductors
34
Properties and uses of iron?
- adding other metals can change its properties
- wrought iron is almost completely pure iron and is malleable, used for gates and railings
- iron corrodes easily
35
Properties of aluminium?
- doesnt corrode easily
- reacts very quickly with oxygen to form aluminium oxide
- used for cans
- light as not dense
- bike frames and aeroplanes
36
Properties of copper?
- good conductor of heat and electricity
- used in electrical currents and wiring as it has low resistance so very efficient
- used i. heating systems
37
What do pure metals not always have?
the properties needed
38
What are alloys?
adding other elements to the metal
39
Describe adding alloys?
new atoms will distort the layers of metal atoms making it more difficult for them to slide over each other
40
How are steels made?
adding small amounts of carbon and sometimes other metals to iron
41
What are the three types of steeel?
low carbon steel, high carbon steel and stainless steel
42
Properties and use of low carbon steel?
easily shaped, car bodies
43
Properties and use of high carbon steel?
- very strong
- inflexible
- hard
- bridges
44
Properties and uses of stainless steal?
corrosion- resistant, hard
| cutlery
45
What does the rate of chemical reaction depend on?
- collision frequency of reacting particles. The more collisions there are the faster the reaction
- energy transferred during a collision
46
What is activation energy?
minimum amount of energy that particles need to react
47
Describe surface area rate practical?
- set up conical flask with dilute HCL, calcium carbonate marble chips with a syringe from the top
- measure volume of gas produced with syringe
- repeat with more mashed up marble chips
48
What is general formula?
- algebraic formula that can describe any member of a family of compounds
CnH2n
49
What is an empirical formula?
simplest whole number ratio of atoms of each eleemnt in a compound
CH2
50
WHat is molecular formula?
the actual number of atoms of each element in a molecule
C2H4
51
What is displayed formula?
shows how atoms are arranged and the bonds between them
52
What is structural formula?
shows arrangement of atoms carbon by carbon with attached hydrogens and functioanal group
CH2CH2
53
What is a homolgous series?
group of compounds that can be all represented by the same general formula
54
What is a functional group?
a group of atoms that determine how a compound typically reacts
55
What are isomers?
have the same molecular formula but atoms are arranged differently
56
what do fuels release energy in?
combustion reactions
57
WHat is the reaction for when hydrocarbons burn in plenitful supply of air?
hydrogen + oxygen = carbon dioxide + water
58
IF there is not enough oxygen for a complete combustion reaction, what happens?
incomplete combustion
59
WHat is the equation for incomplete combustion?
hydrogen + oxygen = water, carbon monoxide, carbon dioxide and carbon
60
What is the problem with carbon monoxide?
can combine to red blood cells and stop your blood from carrying oxygen
61
WHat is acid rain caused by?
sulfer dioxide and nitrogen oxides
62
How are sulfer dioxide and nitrogen oxides produced?
when fractions from crude oils are burned as fuels
63
Where does the sulfer dioxide come from?
sulfer impurities in the hydrogen fuels
64
Where does the nitrogen oxides come from?
created when the temperature is high enough for nitrogen to react with oxygne
65
WHat does nitrogen oxides include?
nitrogen monoxide and nitrogen dioxide
66
What happens when nitrogen oxides and sulfur dioxide mix together with water vapour?
form dilute sulfuric acid and nitric acid
67
What is the problem with acid rain?
causes lakes to become acidic and many plants and animals die as a result
68
What are polymers?
substances of high average ram made by joining lots of small repeating units called monomers
69
WHat type of bond do the monomers in addition polymers have?
double bond
70
What is addition polymerisation?
when unsaturated monomer molecules open their carbon-carbon double bonds and join together to form polymer chains
71
WHat is needed for addition polymerisation?
pressure and catalyst
72
What does ethene become in addition polymerisation?
poly(ethene)
73
What are most polymers?
inert - becuase the carbon to carbon bonds in polymer chain are very strong and arnt easily broken
74
What is problem with polymers?
dont biodegrade easily and release toxic gases when burned so have to be reused
75
What reaction can you do to make insoluble salts?
precipitation reactions
76
What is the precipitation reaction?
using two soluble salts and reacting together to get an insoluble one
77
Lead sulfate word equation?
lead nitrate + magnesium sulfate = lead sulfate + magnesium nitrate
78
Explain how to make lead sulfate?
- add spatula lead nitrate and dissolve in water in test tube. shake
- repeat with magnesium sulfate in different test tube
- mix together in small beaker and stir until lead sulfate precipitates out
- filter in chonical flask
- swill beaker with deionised water to make sure you get all precipitate
- scrape lead sulfate onto fresh filter paper and leave to dry in oven or desiccator
