KS3 chemistry revison Flashcards
1
Q
Define mixture
A
Where particles of different substances are together but not joined
2
Q
Define solvent
A
The liquid
3
Q
Define Solute
A
The soluble solid
4
Q
Define solution
A
Where a solid has dissolved in a liquid
5
Q
Define insoluble
A
A solid that cannot be dissolved
6
Q
Define soluble
A
A solid that can be dissolved
7
Q
What is filtration?
A
A process that removes insoluble solid from a liquid
8
Q
What is crystallisation by evaporation?
A
A process that is used to separate a solute from a solvent (salt from saltwater)
9
Q
What is distillation (evaporation followed by condensation)
A
A process that separates a pure solvent from a solution (water from saltwater)
10
Q
What is chromatography
A
A process that individual solutes from a mixture of solutes in a solvent.
11
Q
What is physical change and an example of it
A
When something changes state and is still reversible most of the time. An example of physical change is ice to water to team because it is reversible.
12
Q
What is chemical change and an example of it
A
When something creates a new substance and then becomes irreversible most of the time. An example of a chemical change is burning wood as it cannot be changed back to wood after being ash.
13
Q
When carbon burns it combines with oxygen to form the compound carbon dioxide. What is the word equation of this reaction.
A
Carbon+Oxygen –> Carbon dioxide
14
Q
Magnesium+Oxygen –>
A
Magnesiumoxide
15
Q
Copper+Oxygen –>
A
Copperoxide
16
Q
What is the name of the reaction that one of the reactants is oxygen
A
Oxidation reactions
17
Q
Sulphur+oxygen –>
A
Sulphur dioxide
18
Q
Phosphorus+oxygen –>
A
Phosphorus dioxide
19
Q
What is the symbol for carbon
A
C
20
Q
What is the symbol for calcium
A
Ca
21
Q
What is the symbol for cobalt
A
Co
22
Q
What is the symbol for copper
A
Cu
23
Q
What are the group 7 elements called
A
Halogens
24
Q
Define corrosion
A
When a metal reacts with oxygen
25
Define rusting
The corrosion of iron
26
Ca+ CI2= CaCI2
Already balanced
27
Pb+Br2=Pb+2Br2
Pb+2Br2+PbBr4
28
AI+O2= AI2 O3
2AI+3O2=2AI O3
29
Ge+F2=GeF4
Ge+2F2=GeF4
30
What is the reactivity series of metals in order
Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Zinc, Iron, Tin, Lead, Copper, Mercury, Silver, Gold, Platinum
31
What is the way to remember the reactivity series of metals in order
Please stop loudly calling my alligator Zac in the Latin classroom my silly goat please
Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Zinc, Iron, Tin, Lead, Copper, Mercury, Silver, Gold, Platinum
32
What is an anomalous result
A result that is very different from the other recorded results
33
What is a repeatable result
A result that you get a similar result again after repeating the experiment at least once
34
What is a reproducible result
Where other people get a similar result after conducting the same experiment
35
What is the hydrogen gas test
Squeaky pop...
- Firstly you collect the gas
- Then get a lit splint and hold it over the gas
- If a squeaky pop is heard then the gas is hydrogen
36
How can you prevent rusting
You can do this by applying oil, using an alloy, apply a dry coating to protect from the rust.
37
What is the reaction for metal and water?
metal+water-->metal hydroxide+hydrogen
38
What happens when metals react with water?
Metal hydroxide and hydrogen are the products. How vigorous the reaction is, reflects how reactive the metal is.
39
What is the reaction of metals and acids?
metal+acid-->metal salt+hydrogen
40
What happens when metals react with acid?
If the metal is very unreactive then the reaction has very little effervesce whereas if they are reactive then the reaction
41
What are displacement reactions?
Displacement reactions involve a metal and a compound of a different metal. A more reactive metal displaces a less reactive metal from its compounds.
42
Why do displacement reactions happen?
The more reactive metal gradually disappears as it forms a solution. The less reactive metal coats the surface of the more reactive metal.
43
Iron chloride+Magnesium-->
Magnesium Chloride+Iron
44
Zinc Chloride+Copper-->
Zinc Chloride+Copper
45
What are the two methods of extracting metals?
Displacement reactions and electrolysis.
46
What is electrolysis?
The flow of an electrical current in a conducting solution or molten liquid which causes chemical changes.
47
How do we decide which method of metal extracting to use?
If the metal is higher on the reactivity series than carbon then electrolysis should be used. An example of this is Aluminium. If the metal is lower on the reactivity series than carbon then you should use displacement reactions.
48
What are catalysts?
They speed up the reaction but do not get used up (their mass stays the same)
49
Why are catalysts used?
They are used to save money in the economy because they use less money.
50
What is an example of a catalyst and what gases does it reduce?
Catalytic converters in cars. This also reduces pollution which is done by changing harmful gases such as carbon monoxide, nitrogen oxides and unburnt fuels into less harmful gases such as carbon dioxide, water, nitrogen.
51
What is the gas test for oxygen?
The glowing splint test. If you light a splint then blow it out. You then need to place it over the substance. If the splint relights then you know that it contains oxygen. This is because you need to have oxygen, heat and fuel for a fire to occur.
52
What is the gas test for Carbon dioxide?
If you bubble the gas through limewater and if it turns cloudy then carbon dioxide is present.
53
Iron, magnesium and gold are examples of metal elements. Metals have properties in common. What are they?
Shiny, good conductors of electricity and heat, malleable.
54
What properties do most metals have in common?
Solid at room temperature (except mercury), hard, strong, high density and are sonorous (able to make a ringing sound when hit).
55
Oxygen, carbon, sulfur and chlorine are examples of non-metal elements. Non-metals have properties in common. What are they?
Dull, poor conductors of heat and electricity, weak and brittle
56
What properties do most non metals have in common?
Low density, and not sonorous (they do not make a ringing sound when hit)
57
What is the word equation for the reaction of non metals and oxygen (non metal oxides)?
non metal+ oxygen-->non metal dioxide
58
What are rocks made from and what are in them?
They are made of grains that fit together. Each grain in a piece of rock is made from a mineral, which is a chemical compound.
59
How can the grains in a rock vary?
They can have different colours, shapes and sizes
60
What are the two types of grains and an example of a rock from each?
Interlocking grains (granite) and rounded grains (sandstone)
61
What are the two types of rocks?
Porous and non-porous rocks
62
What type of grains of rocks absorb water better?
Rocks with rounded grains are more likely to absorb water than rocks with interlocking grains. This is because the water can get into the gaps between the grains.
63
What type of rocks and grains are more soft?
Rocks with rounded grains are usually softer and more crumbly than rocks with interlocking grains. So porous rocks tend to be softer than non-porous rocks.
64
How are igneous rocks formed?
Igneous rocks are formed from molten rock that has cooled and solidified. When the magma cools enough, it solidifies and igneous rock forms.
65
What type of crystals are igneous rock c?
Igneous rocks contain randomly arranged interlocking crystals.
66
How does the size of the crystals of igneous rock depend on how quickly the molten magma solidifies?
Magma that cools slowly will form an igneous rock with large crystals. Lava that cools quickly will form an igneous rock with small crystals
67
What are the two types of igneous rock?
Intrusive and extrusive
68
What does an extrusive igneous rock mean?
Extrusive igneous rocks form from magma that erupted onto the surface as lava, where it cooled quickly. The size of these crystals are small and some example of extrusive igneous rocks are obsidian and basalt.
69
What does an intrusive igneous rock mean and what are some examples?
Intrusive igneous rocks form from magma that cooled slowly, deep underground in the earths crust. They have large crystals and some examples of intrusive igneous rocks are granite and gabbro.
70
Can igneous rocks contain fossils? Explain why.
Igneous rocks do not contain any fossils. This is because any fossils in the original rock will have melted when the rock melted to form magma.
71
How are sedimentary rocks formed? (short)
Sedimentary rocks are formed from the broken remains of other rocks that become joined together.
72
What is the full process of the sedimentation?
A river carries, or transports, pieces of broken rock as it flows along. When the river reaches a lake or the sea, its load of transported rocks settles to the bottom. We say that the rocks are deposited. The deposited rocks build up in layers, called sediments.
73
What is the full process of the cementation?
The weight of the sediments on top squashes the sediments at the bottom. This is called compaction. The water is squeezed out from between the pieces of rock and crystals of different salts form. The crystals stick the pieces of rock together.
74
How long does it take for sedimentary rocks to form?
Millions of years
75
What is the process order of the formation of sedimentary rocks?
transport → deposition → sedimentation → compaction → cementation
76
What type of grains form sedimentary rocks?
Rounded grains in layers
77
Can sedimentary rocks contain fossils? Explain why.
Sedimentary rocks may contain fossils of animals and plants trapped in the sediments as the rock was formed. This is due to the long time frame that is taken to built and form this type of rock.
78
What are 4 examples of sedimentary rocks?
Chalk, Limestone, Shale, Sandstone
79
How are metamorphic rocks formed?
Metamorphic rocks are formed from other rocks that are changed because of heat or pressure. They are not made from molten rock – rocks that do melt form igneous rocks instead.
80
How are metamorphic rocks put under pressure and how does it change?
Earth movements can cause rocks to be deeply buried or squeezed. As a result, the rocks are heated and put under great pressure. They do not melt, but the minerals they contain are changed chemically, forming metamorphic rocks.
81
What is an example of a metamorphic rock and what was it before?
Marble is formed from limestone and contains tiny interlocking grains.
82
Slate is a metamorphic rock. What was it before and how can it be useful for buildings?
The layers in slate, formed from shale, are arranged in layers. This makes slate useful for making roof tiles because it can be split into separate flat sheets.
83
Can metamorphic rocks contain fossils? Explain why.
Metamorphic rocks rarely contain fossils. Any that were present in the original sedimentary rock will not normally survive the heat and pressure.
84
What is sublimation?
This means that they go straight from solid to gas without passing through the liquid state.
85
What substances sublime?
Iodine, carbon dioxide, plug in air fresheners, ink in printers and photocopiers, comets as they approach the Sun
86
What is condensation?
If you cool a gas into a liquid
87
What is thermal decomposition and an example?
Thermal decomposition is when substance breaks into simpler substances when it is heated.
Calcium carbonate = Calcium oxide + Carbon dioxide
88
What is an exothermic reaction?
Where energy in a reaction is released into the outside area which makes substances hotter in the outside area
89
What is an endothermic reaction?
This is where the reactions energy is taken into the reacting substances so it enters the reaction.
90
What is a neutralisation reaction definition and an example equation?
Acid + base --> base will dissolve to form an alkali
Hydrochloric acid + sodium hydroxide → sodium chloride + water
HCl + NaOH → NaCl + H20
91
What is the Law of Conservation of mass?
The mass of the reactants should be equal to the mass of the products
92
What is a physical property? Give some examples.
A physical property is something that does not change the chemical identity. An example is boiling point as it is still H2O.
93
What is a chemical property? Give some examples
A chemical property is something that does change the chemical identity. An example is flammability as something new is created.
94
What phrase describes a solution with a pH of 14?
Very alkali
95
What phrase describes a solution with a pH of 1?
Very acidic
96
What phrase describes a solution with a pH of 7?
Neutral
97
Magnesium is above iron in the reactivity series. What does this tell you about the two elements?
iron can be used to extract magnesium from its ore
98
Hydrochloric acid reacts with sodium hydroxide.
| What are the products of this reaction?
Sodium chloride + water
99
Hydrochloric acid reacts with sodium hydroxide.
| What is the name for this type of reaction?
Neutralisation
100
What would be formed in a reaction between hydrochloric acid and magnesium?
Magnesium chloride + hydrogen
101
Describe three important, useful properties of ceramics.
Good insulators of heat and electricity, high melting point and strong when squished
102
What are polymers and what are some example and some properties?
Polymers are made up of molecules with long chains of repeated groups of atoms. These are plastic, rubber and polythene. Some examples of properties are they are strong, unreactive and waterproof.
103
What are composites and what are some example and some properties?
Composites are materials made up of combinations of two or more materials. These are such as concrete, paper and glass. A composite material usually contains properties of the materials that went into it.
104
What are the physical properties? (9)
Boiling point, melting point, ductility, malleability, colour, viscosity, density, mass/weight, volume
105
What are the chemical properties? (8)
Flammability, corrosive, combustible, explosive, colour change, PH, taste
106
Describe how Mendeleev sorted out the elements into his version of the periodic table. [4 marks]
Mendeleev sorted the elements into his own version of the periodic table in increasing order of atomic mass ; however, Mendeleev swapped some around so that they lined up in groups with similar chemical properties. Also, the metals are placed on the left of the periodic table leaving the right side to occupy the non-metals. The actual table is sorted into rows and columns, the rows are called periods and the columns are called groups. Mendeleev also left spaces in his periodic table because he acknowledged that there were some undiscovered elements. However, Mendeleev could estimate the properties of these gaps due to the placements and the similarities between the elements.
107
Which statement about the periodic table is not true?
A there are more metal elements than non-metal elements
B the metals are on the right of the table and the non-metals on the left
C metals such as iron, copper and gold are all transition metals
D metals such as sodium and magnesium are not transition metals
D metals such as sodium and magnesium are not transition metals
108
```
Which gas is not found in the atmosphere?
A oxygen
B nitrogen
C hydrogen
D carbon dioxide
```
C hydrogen
109
What are groups and periods in the periodic table?
Groups in the periodic table mean the columns. The periods are also known as the rows.
110
Which is the most common element in the earth?
Oxygen
111
Which is the most common element in the atmosphere?
Nitrogen
112
What does the zig zag line on the table show?
Metals and non metals
113
Is the group on the right side of the table more or less reactive than the left?
They are more reactive
114
In which state of matter particles have most energy?
Gas
115
In which state of matter particles NOT be squished together?
Solid and liquid
116
In which state of matter do the particles move around the least?
Solid
117
In which state of matter does the object fill up the whole container it is in?
Gas
118
In which state of matter does the object keep its shape no matter where it is put?
Solid
119
In which state of matter do the particles flow?
Liquid and gas
120
What is needed to overcome the forces holding particles the particles together when solids change into liquids?
Energy
121
What happens to the energy when a liquid turns back to a solid and what happens to the temperature?
It is no longer needed so it transfers to the surrounding areas and the temperature stays the same.
122
What happens when a solid is heated?
It expands and then it expands further when it forms a liquid
123
What happens when water cools down?
It contracts until it reaches 4 degrees celsius and then he starts to expand again. When the ice forms it takes up more space than water as it is less dense than water
124
Define atom
The smallest particle of a chemical element that can exist
125
Define element
A pure substance consisting only of atoms that all have the same numbers of protons in their atomic nuclei.
126
Define compound
A compound is composed of atoms from more than one element held together by chemical bonds.
