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operation grade 9 > Chemistry paper 1 > Flashcards

Chemistry paper 1 Flashcards

1
Q

what does (s) stand for?

A

solid

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2
Q

what does (l) stand for?

A

liquid

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3
Q

what does (g) stand for?

A

gas

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4
Q

what does (aq) stand for?

A

aqueos

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5
Q

what is the chemical formula for water?

A

H20

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6
Q

CO2 is the chemical formula for what molecule?

A

carbon dioxide

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7
Q

what is the chemical formula chlorine?

A

Cl2

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8
Q

what is the chemical formula ammonia?

A

NH3

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9
Q

what is the chemical formula for hydrogen?

A

H2

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10
Q

what is the chemical formula for oxygen?

A

O2

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11
Q

NH4^+ is the chemical formula for what molecule?

A

ammonium

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12
Q

NO3^- is the chemical formula for what molecule?

A

nitrate

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13
Q

What is the chemical formula for sulfate?

A

SO4^2-

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14
Q

What is the chemical formula for hydroxide?

A

OH^-

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15
Q

what is the chemical formula for carbonate?

A

CO3^2-

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16
Q

What did John dalton describe atoms as at the start of the 19th century?

A

solid spheres

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17
Q

Who disproved that atoms were indivisible theory and in what year?

A

J J Thomson and in 1897

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17
Q

Who disproved that atoms were not indivisible and in what year?

A

J J Thomson and in 1897

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18
Q

What idea did J J Thomson come up with in 1897?

A

The plum pudding method.

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19
Q

In 1909 who conducted the golden foil experiment?

A

Ernest Rutherford and his 2 students Geiger and Marsden

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20
Q

What did the Golden foil method show and prove?

A

It showed more particles deflected then expected and some deflected back. This disproved the plum pudding method.

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21
Q

What theory did the golden foil method lead to Rutherford believing?

A

The nuclear atom theory

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22
Q

What did the nuclear atom theory tell us?

A

That there is a tiny positively charged nucleus with a cloud of negative electrons and that an atoms is mainly empty space.

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23
Q

Which scientist further adapted Rutherford’s method?

A

Bohr

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24
Q

what did Bohr propose of a new model?

A

Electrons can only exist in fixed orbits or shells, not in between, each shell also has a fixed energy.

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25
Q

Where is the nucleus?

A

In the middle of the atom

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26
Q

What is contained in the atom?

A

Protons and neutrons

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27
Q

Where are electrons in an atom?

A

They are around the nucleus and move in shells.

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28
Q

Are atoms neutral?

A

Yes atoms are neutral.

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29
Q

Do isotopes have a different amount of protons, electrons or neutrons?

A

Neutrons

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30
Q

Who made the first periodic table and when did they make it?

A

Dmitri Mendeleev and in 1869

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31
Q

How did Mendeleev order his periodic table?

A

He ordered it based on the properties of the chemical?

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32
Q

What did Mendeleev realise when putting elements in atomic mass?

A

He realised that it had started to create a pattern

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33
Q

Some elements ended up in wrong columns when Mendeleev put them by atomic mass why?

A

This was because he was using an elements isotopic version.

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34
Q

Why did Mendeleev leave gaps in his table?

A

For missing elemnts

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35
Q

In the periodic table which groups are most likely to form ions?

A

groups 1 and 2 and 6 and 7

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36
Q

What is ionic bonding?

A

When a metal and a non metal react together

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37
Q

What structure do ionic compounds always have?

A

A giant ionic lattice

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38
Q

What properties do ionic compounds have and why?

A

They have high melting and boiling points due to their strong attraction

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39
Q

Why do ionic compounds carry an electric charge when liquefied but not when solidified?

A

This is because in a liquid the particles are free to move about and carry charge but can not do this when they are in a large solid lattice?

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40
Q

What properties do a covalent bond have?

A

Low boiling and melting points

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41
Q

what type of elements form a covalent bond?

A

two non metals

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42
Q

Why don’t molecular compounds conduct electricity?

A

They don’t conduct electricity because they do not contain any free electrons or ions.

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43
Q

What chains are polymers made out of?

A

Covalently bonded carbon chains

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44
Q

What’s the disadvantage of dot and cross diagrams?

A

They do not usually show anything about atom size or how they are arranged.

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45
Q

What’s the problem with 3d diagrams?

A

They only show the outer layer of the substance.

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46
Q

What’s the problem with the 2d representations?

A

They do not show you the shape of the substance or give you an idea about the size of the atom

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47
Q

why are ball and stick diagrams useful?

A

Great for visualisation and more realistic than a 2d diagram.

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48
Q

Whats the problem with 2d diagrams?

A

They make it look like there are big gaps between the atoms when the are not. They also do not show the correct scales of atoms or ions.

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49
Q

With a simple molecular substance what happens when the molecules get bigger?

A

The intermolecular force increases, this means that more energy will be needed in order to break them.

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50
Q

What state of matter are most molecular substances at room temperature?

A

either gases or liquids.

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51
Q

What is buckminsterfullerenes chemical formula and how many hexagons and pentagons is in its ball?

A

It has a molecular formula of C60 and is made of 20 hexagons and 12 pentagons.

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52
Q

How many covalent bonds do diamonds have and what structure does it have?

A

4 strong covalent bonds and a high melting point. It also has a rigid lattice structure.

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53
Q

how many covalent bonds does graphite have and what structure?

A

3 covalent bonds a creates a sheet of carbon atoms arranged in hexagons, they are weakly held together so are free to move of each other

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54
Q

What 2 properties does graphite have?

A

soft and slippery ideal lubricating material and has a high melting point.

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55
Q

What structure does graphene have?

A

one layer of graphite, and a sheet of carbon atoms joined in hexagon, the sheet is one atom thick.

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55
Q

What structure does graphene have?

A

one layer of graphite, and a sheet of carbon atoms joined in hexagon, the sheet is one atom thick.

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56
Q

What electrons does metallic bonding involve?

A

Delocalised electrons

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57
Q

What properties do most non metals share?

A

dull look, brittle and low boiling points, most do not conduct electricity and often have lower densities.

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58
Q

Do non metals gain or lose electrons?

A

They gain electrons

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59
Q

do metals tend to lose or gain electrons?

A

They lose electrons.

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60
Q

What happens to atoms during a chemical reaction?

A

Nothing as atoms are not created or destroyed

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61
Q

When does a reaction stop?

A

When all the reactant has been used up

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62
Q

True or false solids have a strong force of attraction?

A

True

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63
Q

True or false liquids have no force of attraction?

A

False- they have a small for of attraction

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64
Q

True or false gases have the strongest for of attraction?

A

False- they have no force of attraction

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65
Q

Do particles in a solid move from their position?

A

No they keep a definite shape and volume

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66
Q

can particles in a liquid move position?

A

Yes they can as they have no definite shape however they do keep the same volume

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67
Q

Do gasses have the ability to move from their first position?

A

They do not have a definite shape or volume and will always fill any container (a gas will escape from a container if it is not air tight)

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68
Q

Can particles vibrate in a solid?

A

Yes they do have the ability to vibrate if the solid is heated up.

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69
Q

What happens to particles in a liquid when they heat up?

A

The particles start to move faster and faster as the liquid heats up and it does slightly expand.

70
Q

What is it called when a liquid transforms into a gas?

A

Evaporating

71
Q

What is it called when a gas transforms into a liquid?

A

Condensing

72
Q

What is it called when a solid transforms into a gas?

A

Subliming

73
Q

What is it called when a liquid transforms into a solid?

A

Freezing

74
Q

What does pure mean in chemistry?

A

when something is completely made up of one single element or compound

74
Q

How can you test purity?

A

using melting points as a pure substance has a specific sharp melting and boiling point.

75
Q

What is fractional distillation used for?

A

the separation of a mixture of liquids

76
Q

What does simple distillation separate?

A

solutions

77
Q

What is filtration used for?

A

The separation of an insoluble solid from liquid.

78
Q

What does crystallisation separate?

A

a soluble solid from a solution

79
Q

How do you do filtration?

A

put filter paper in funnel pour liquid with insoluble substance through.

80
Q

how does simple distillation work?

A

pur seawater in flask, set up apparatus, gradually heat flask, water vapour will pass through a condenser where it condenses and gets collected, this occurs till you are left with salt in the flask

81
Q

How does fractional distillation work?

A

put mixture in flask, and set up apparatus, gradually heat the flask, due to different boiling points you will need to gradually increase, as when the first evaporates and reaches the top it will condense and run back down.

82
Q

how do you do crystallisation?

A

pour solution into dish and gently heat,, once some water has evaporated solution becomes more concentrated, when it starts to evaporate or crystals start to form remove dish from heat and leave solution to cool. , as salt becomes insoluble it should form crystals, filter the crystals and out them in a dry place.

83
Q

How many phases are in chromotography?

A

there are two phases

84
Q

what is a mobile phase?

A

Where the molecules can move, (liquid or gas)

85
Q

What is a stationary phase?

A

where molecules can not move, (solid or thick liquid)

86
Q

What is surface water?

A

lakes, rivers and reservoirs

87
Q

what is groundwater?

A

Aquafiers

88
Q

what is waste water?

A

water that has been contaminated

89
Q

where is water purified?

A

In water treatment plants

90
Q

what is filtration when purifying water?

A

a wire mesh that screens out large twigs and the gravel and sand beds filters out the rest.

91
Q

what is sedimentation in water purification?

A

iron sulfate or aluminium sulfate is added to the water, it makes fine particles clump together and settle at the bottom.

92
Q

what is chlorination?

A

a chlorine gas gets bubbled through to kill any harmful bacteria

93
Q

How can you get potable water?

A

by distilling sea water

94
Q

how can you distill sea water?

A

Lots of energy, meaning lots of money is needed.

95
Q

what sort of water is needed in chemical analysis?

A

Pure water

96
Q

What is deionised water?

A

Water that has had the ions removed

97
Q

what does the ph scale go from and go to

A

0-14

98
Q

what numbers represnt strong acids on the pH scale?

A

0-3

99
Q

what numbers represnt weak acids on the pH scale?

A

4-6

100
Q

what number on the pH scale represnts neutral?

A

7

101
Q

What numbers are weak alkalines on the pH scale?

A

8-11

102
Q

What numbers are strong alkalines on the pH scale?

A

12-14

103
Q

What do acids and bases do to each other?

A

They neutralise each other out

104
Q

what do acids produce in water?

A

hydrogen ions

105
Q

what happens to strong acids in water?

A

they ionise completly around 0-3 pH

106
Q

what happens to weak acids in water?

A

do not fully ionise only a small proportion disscoaite and release H^+ ions. have a pH around 3-6

107
Q

What is the difference between the strength and concentration of an acid?

A

strength tells you what proportion of acid molecules ionise in the water and concentration means how much acid there is per litre,

108
Q

What does it mean if you have more moles per decimetre in your acid?

A

It means it is more concentrated

109
Q

When do salts form?

A

when acids react with bases or when an acid reacts with metals or metal carbonates

110
Q

what is concentration measured in?

A

in g dm^-3 or mol dm^-3

111
Q

are the common salts of sodium, potassium and ammonium soluble? if no which ones aren’t

A

yes

112
Q

Are nitrates soluble? if no which ones aren’t

A

yes

113
Q

are common chlorides soluble? if no which ones aren’t

A

yes some are, but silver chloride and lead chloride are not

114
Q

are common sulfates soluble? if no which ones aren’t

A

yes apart from lead sulfate, barium sulfate and calcium sulfate

115
Q

are common carbates soluble?

A

No, except for soidum, potassium and ammonium

116
Q

How do you make insoluble salts (method)?

A

1) add a spatula of lead nitrate to a test tube, add water to dissolve it, (use dionised water), shake thoroughly till disolved, in seperate tube do same with sodium chloride.
2) put twi solutions in a small beaker and give good stir to make sure its all mixed togther, lead chloride should precipitate out
3) put a folded piece of filter paper into filter funnel and stick funnel into a connical flask
4) pour contens of beaker through filter paper, make sure doesn’t go above filter paper
5) swill out beaker with more deionised water, tip into filter to get out all precipitate.
6) rinse out contents of filter paper with deionised water to make sure all soluble sodium nitrates have washed away.
7) scrape lead chloride onto fresh fi;lter paper and leave it to dry in an oven or desiccator.

117
Q

what two things are included in electrolysis?

A

oxidation and reduction

118
Q

What is electrolysis?

A

the breaking down of substances by using electricity

119
Q

what happens to positive ions in electrolysis?

A

the positive ions move towards the cathode and become reduced

120
Q

what happens to negative ions in electrolysis?

A

the negative ions move towards the anode and become oxidised.

121
Q

What do half equations show?

A

How electrons have transferred during a reaction.

122
Q

What else do we get in electrolysis of aqueous solutions?

A

hydrogen ions and hydroxide ions.

123
Q

why do masses of non inert electrodes change during electrolysis?

A

the anode loses mass as copper dissolves, and the cathode gains mass as copper is deposited

124
Q

What is a redox reaction?

A

A chemical reaction that occurs between an oxidizing compound and a reducing compound

125
Q

What takes place during a displacement reaction?

A

A more reactive element will displace/push out the less reactive compound.

126
Q

What is oxidation in terms of electrons?

A

Oxidation is the loss of electrons

127
Q

What is reduction in terms of electrons?

A

gain of electrons, loss of oxygen or gain of hydrogen

128
Q

True or false the easier it is for a metal atom to form a positive ion the more reactive it will be

A

True

129
Q

Describe oxidation in the terms of adding and removing oxygen?

A

losses electrons and hydrogen but gains oxygen

130
Q

Describe reduction in the terms of adding and removing oxygen?

A

gains electrons and hydrogen and loses oxygen

131
Q

Where do you find the least reactive elements in a reactive series?

A

bottom and are more resistant to oxygen

132
Q

What is metal ore and where can you normally find it?

A

A metal ore is a material with all the materials removed from it (done to get desired materials). Normally found inside the earth’s crust

133
Q

How are metals more reactive than carbon extracted from their ores?

A

They are extracted by electrolysis.

134
Q

How are metals less reactive than carbon extracted from their ores?

A

They are heated up with carbon

135
Q

Give 2 biological methods used for the extraction of metals from low grade ones?

A

Bioleaching and phytoextraction.

136
Q

give an example of why electrolysis is better than bioleaching?

A

Easier and can do metals with higher reactivity than carbon

137
Q

Give an example on why electrolysis is worse than bioleaching?

A

It is more expensive and isn’t as slow

138
Q

Give 2 ways that recycling is better for the environment than landfill?

A

conserves our resources and our energy, protects the environment

139
Q

How can recycling benefit the economy?

A

saves money, massive industry creating a lot of jobs

140
Q

What is a life cycle assessment?

A

looks at each stage of life with the product from taking the material from natural raw materials to making the product from the material and using the product and disposing the product.

141
Q

Give 4 factors that should be considered when drawing up a life cycle assessment?

A

choice of material manufacturer, product use and the disposal of the product should be the 4 considered factors

142
Q

What does Le Chatelier’s principle state?

A

that if there is a change in concentration, pressure or temperature in a reversible reaction the equilibrium position will move to help cuntract that change.

143
Q

What symbol shows a reversible reaction?

A

symbol ⇌

144
Q

What happens to the equilibrium of a reaction if the reactants concentration is increased?

A

The position of equilibrium will change

145
Q

If the position of equilibrium for a reversible reaction lays to the right what does this tell us about the amount of reactants and the products that are present?

A

It increases the yield.

146
Q

Give 2 examples of transition metals?

A

copper, iron, zinc, gold silver and platinum (there are more too)

147
Q

What 2 properties do transition metals have in common with most other metals?

A

Hard, strong, shiny and malleable are shared properties

148
Q

what two physical properties do transition metals have that most metals do not?

A

high melting points and also having high densities

149
Q

what is an alloy?

A

An alloy is the combination of two or more nonmetals

150
Q

why are alloys usually stronger than pure metals?

A

The smaller atoms upset the larger atoms and make it harder for them to slip over each other

151
Q

Give a use of: bronze

A

make medals, decorative ornaments and statues

152
Q

Give a use of: brass

A

water taps and door fittings

153
Q

Give a use of: magnalium

A

cars and aeroplanes if has about 5% magnesium and if has 50% or more it is used in fireworks.

154
Q

why is rusting a redox reaction?

A

Because the metals lose an electron.

155
Q

give two ways rusting can be prevented?

A

Using oil puts a protective layer stopping oxygen getting to it or use calcium chloride as it stops the water in the air

156
Q

give two main reasons why an object might be electroplated?

A

to contain metal ions and to stop objects erroding easily

157
Q

Why do we not use universal indicator in titrations?

A

changes colour gradually and you want a single colour change

158
Q

What colour change would you see in a titration when the acid has been neutralised and you had added phenolphthalein?

A

it goes from pink to colourless

159
Q

State the percentage yield formula?

A

percentage yield=actual yield/theoretical yield *100

160
Q

What does theoretical yield mean?

A

the theoretical yield is the mass of products a reaction should be producing

161
Q

What does it mean if the percentage yield of a reaction is 100%?

A

the reaction would have produced the theoretical yield

162
Q

Why is a percentage yield always less than 100%?

A

The loss of products during recovery and competing reactions

163
Q

What formula is used to work out the atom economy of a reaction?

A

mass of atoms in desired product/mass of atoms in product x100

164
Q

Why aren’t reactions that have low atom economies usually profitable?

A

The resources are used up very quickly

165
Q

What chemical is used for manufacturing during the Haber process?

A

Hydrogen and nitrogen

166
Q

Why are conditions used in a Haber process a compromise between rate and yield?

A

Because it is better to wait shorter and get a similar amount then waiting a lot longer and getting slightly more

167
Q

3 ways to increase the rate of attainment of equilibrium?

A

change the temperature, pressure or concentration

168
Q

2 compounds used in fertilisers?

A

nitrogen,phosphorus and potassium

169
Q

What is the molar volume of gas?

A

one mole of gas

170
Q

What does one mole of gas occupy at room temperature?

A

24dm^3

171
Q

what is the only product of reaction in a hydrogen-oxygen fuel cell?

A

water.

172
Q

What element is added to iron to make steel?

A

carbon

operation grade 9 (13 decks)

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