Chemistry Paper 1 Flashcards

1
Q

Chem: what is the equation for atom economy

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Chem: what type of atoms are used in and what happens in covalent bonding

A

2 or more non-metals, sharing electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Chem: what happens in metallic bonding and in what type of atoms

A

Positive metal ions in a sea of delocalised negative electrons, in metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Chem: what happens in ionic bonding and in what type of atoms

A

Gives/takes electrons, metals and non-metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Chem: what is a activation energy

A

The minimum energy required to start a chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Chem. what is an energy profile

A

A graph showing energy change during a chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Chem: what is an exothermic reaction

A

A chemical reaction that releases energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Chem: what is an endothermic chemical reaction

A

A chemical reaction that takes in energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Chem: what happens in a chemical reaction

A

Bonds are broken and formed and atoms are rearranged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Chem: how thick is one nm in terms of atoms

A

10 atoms thick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Chem: order in terms of size, from smallest to largest, coarse particles, nano particles and fine particles

A

Smallest - largest: nanoparticles, fine particles, coarse particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Chem: what is the size of coarse particles

A

2500 to 10000 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Chem: what is the size of fine particles

A

100 to 2500 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Chem: what is the size of nano particles

A

1 to 100 nm thick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Chem: is the anode the positive or negative electrode in electrolysis

A

Positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Chem: is the cathode positive or negative in electrolysis

A

Negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Chem: is an anion positive or negative

A

Negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Chem: is a cation positive or negative

A

Positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Chem: what happenes at the negative electrode in electrolysis of aqueous solutions

A

Hydrogen forms , only if the metal is more reactive than it
Also electrons transferred to ion to make it an atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Chem: is electrolysis of aqueous solutions what happens at the positive electrode

A

Oxygen produced, unless a halogen present then the halogen is produced
Electron transferred from ion to positive electrode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Chem: what is an aqueous solution

A

Something dissolved in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Chem: what is the definition of electrolysis

A

Electrolysis is the process of splitting ionic compounds using electric current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Chem: how do you work out moles of an atom

A

Moles= mass / formula mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Chem: how do you work out the formula mass (Mr) of a molecule

A

It is the sum of the elements in the molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Chem: work out the Mr of K ₂O if the formula mass of of K is 39 and O is 16

A

39+39+16=94

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Chem: How do you write ionic equations

A

Split the equation so
- NaOH ( aq ) + HNO 3 ( aq ) → NaNO 3 ( aq ) + H 2 O ( l )
Would become - Na + OH ( aq ) + H + NO 3 ( aq ) → Na + NO 3 ( aq ) + H 2 + O ( l )
Then cross out the portions that do not change their charge, this becomes
- OH ( aq ) + H → H 2 O ( l )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Chem: what is an ionic equation

A

It is a chemical equation with all of the things that do not change state removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Chem: what is oxidation

A

Oxidation is the loss of electrons and the gain of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Chem: what is reduction

A

It is the gain of electrons and hydrogen and the loss of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Chem: in electrolysis does reduction or oxidation occur at the positive electrode

A

Oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Chem: in electrolysis does oxidation or reduction occur at the negative electrode

A

Reduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Chem: what is a half equation

A

Electrons are represented, they are 2 equations that show how electrons are transferred at each electrode in electrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Chem: what is the equation for complete combustion

A

Hydrocarbon + oxygen -> carbon doxide + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Chem: what is the equation for incomplete combustion

A

Hydrocarbon + oxygen -> carbon doxide + water + carbon monoxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Chem: what is the definition of carbon footprint

A

this is the total amount of carbon dioxide and other greenhouse gases that are emitted over the full lifecycle of a product, service or event

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Chem what is carbon foorptprint offsetting

A

Say you buy a plane ticket, planting trees to offset the greenhouse gasses released by the journey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Chem: what is the order of events for the formation of life

A

Volcanoes, oceans, algiae, plants, animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Chem: what are the percentages of gasses in the atmosphere

A

Nitrogen-78, oxygen-21, other gasses-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Chem: what are the 4 alkanes you need to remember

A

Methane, ethane, propane, butane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Chem: what is crude oil made of

A

Fossilised plankton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Chem: what is the definition of a mixture

A

A substance composed of 2 or more differeent compounds or elements not chemically bonded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Chem: what is ionic bonding and in what types of elements does it occur

A

Giving/taking electrons
Between metals and non metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Chem: what is covalent bonding and in what type of elements does it occur

A

Sharing electrons
2 non metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Chem: what is metallic bonding and in what type of elements does it occur

A

Sea of delocalised electrons
Metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Chem: what are the properties of covalently bonded substances

A
  • Non-conductive(no charged particles that can carry a charge)
  • low melting point
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Chem: what are the properties of ionically bonded substances

A

Conduct when dissolved in water, hard and brittle, high melting and boiling points.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Chem: what defines potable water

A

It is safe to drink, it should have low levels of dissolved salts and of microbes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Chem: what are the 2 ways of getting potable water from salt water

A

Distillation , reverse osmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Chem: what is reverse osmosis

A

It is osmosis where the water moves from low to high concentration because of large amounts of pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Chem: what is distillation

A

Where a liquid is evaporated and collected from a mixture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Chem: what are the 3 ways water us steralized

A

UV, chlorine, ozone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Chem: what is pure water

A

Water that is not in a mixture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Chem: how many cm3 in a dm3

A

1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Chem: how do catalysts work

A

They change the reaction pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Chem: what are the 5 factors that affect rate of reaction

A

-temp
-concentration
-catalyst
-pressure
-surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Chem/bio: how do enzymes make things react

A

They lower the activation energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Chem: what is a the difference between weak and strong acids

A

Weak acids have low amounts of ionised hydrogen ions, whereas in strong acids there is a large amount of ionised hydrogen ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

chem: what is a mole

A

1 mol is the amount of substance that contains the same number of particles as there are atoms in 12.0 g of carbon-12, its the 6.02 x10^23 atoms of carbon 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

chem: what is percentage yield

A

actual yield / theoretical yield x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

chem: what is the equation for relative formula mass

A

adding up all of the relative atomic masses of the atoms in a formula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Chem: what is the difference in amount of hydrogen ions between PH 2 and PH 1

A

10x, each jump is a gap of 10x as it is what i think is a log arythem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Chem: what hydrogen ions constitute acids, are they positive or negative

A

H+ ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Chem: what hydrogen ions constitute alkalise, shat charge are they

A

OH- ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

chem: in electrolysis does reduction happen at the cathode or anode

A

cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

chem: in electrolysis does oxidation happen at the cathode or anode

A

anode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Chem: what is the difference between giant and simple covalent bonding

A

Simple covalent - fixed number of atoms in the structure, giant covalent - undefined amount of atoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Chem: why do simple covalent compounds have low melting and boiling points

A

The have weak intermolecular forces, this means less energy is needed to overcome these forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Chem: what is the difference between atomic and intermolecular forces

A

Atomic forces are forces within an atom and intermolecular forces are the forces between atoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Chem: what are the properties of simple covalent compounds

A

Low melting and boiling point, do not conduct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Chem: what are the properties of giant covalent

A

High melting and boiling point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Chem: what are the properties of ionic compounds

A

High melting and boiling points, when molten or dissolved the conduct, when solid the have poor conductivity

72
Q

Chem: what are the properties of metallic bonding

A

Conductivity

73
Q

Chem: define concentration

A

Amount of particles in a given volume

74
Q

Chem: to increase the rate of reaction for an Exothermic reaction by changing temp what do you do, cool or heat? Why?

A

Cool, if there is less energy in the surroundings it is easier for the reaction to give out energy.

75
Q

Chem: what is a solvent

A

A liquid in which a solid dissolves

76
Q

Chem: what is a solute

A

Dissolved solid

77
Q

Chem: what is a solution

A

A liquid which contains a dissolved solid

78
Q

Chem: what are the 5 ways of separating mixtures

A
  • crystallisation
  • filtration
  • chromatography
  • simple distillation
  • fractional distilation
79
Q

Chem: explain fractional distillation

A

A mixture of several substances is separated by distilling the mixture and then evaporating and collecting the individual components using their individual boiling points

80
Q

Chem: define distillation

A

Purifying a liquid by heating and cooling

81
Q

Chem: explain simple distillation

A

It separates 2 liquids with different boiling points, the mixture with the lower boiling point is boiled off and collected

82
Q

Chem: explain crystalizatiom

A

To separate a soluble substance from a solvent, evaporate the solvent to form crystals of the solute

83
Q

Chem: explain filtration

A

Used to separate an insoluble solid from a liquid, the mixture is put through a filtration device to collect the liquid and the solid/s

84
Q

Chem: explain chromatography

A

Used to separate mixtures of soluble substances in a solution, paper chromatography this works on the principle that some substances are more soluble

85
Q

Chem: what is the equation of concentration (used in titrations)

A

Concentration = moles / volume

86
Q

Chem: define decomposition

A

The process of breaking down

87
Q

Chem: what is thermal decomposition

A

A compound that breaks down when heated

88
Q

Chem: what are the 2 catalysts used in catalytic converters

A

Palladium and platinum

89
Q

chem: what are the properties of the transition metals

A
  • they have high melting and boiling points
  • higher dencity
  • lower reactivity
  • greater strength and hardness
  • some of them can be used as catalysts
90
Q

chem: what is an acid

A

it is a substance that forms H+ ions when dissolved in water

91
Q

chem: waht is an alkali

A

it is a substance that forms OH- ions when dissolved in water

92
Q

chem: when reacting with other substances what charged ions do metal atoms form

A

posotive

93
Q

chem: what is the reactivity of a metal baced on

A

its ability to form its posotive ion

94
Q

chem: what is an ion

A

it is an atom or group of them that has any charge

95
Q

chem: what is a spectator ion

A

it is an ion that, in a reaction does not change its charge

96
Q

chem: what is the difference between an alkali and a base

A

a bace is an alkali that is soluable in water

97
Q

chem: when lithium reacts with water what happens

A

fizzes steadily and floats

98
Q

chem: when potassium reacts with water what happens

A

reacts quickly, hdrogen produced is instantly ignited and the metal ignites too, buring with a lilack flame

99
Q

chem: when sodium reacts with water what happens

A

fizzes rapidly and melts, moves around on the waters surface

100
Q

chem: why are metals less reactive than carbon extracted from their ore by carbon

A

the metal is reduced (looses its oxygen). carbon (in the form of coal) is used because it is cheap and abundent

101
Q

chem: when acids react with metals what is formed

A

hydrogen and a salt

102
Q

chem: what are the 3
types of base that acids can be neutralised with

A
  • metal carbonates
  • metal oxides
  • metal hydroxides
103
Q

chem: acid + metal oxide ->

A

salt + water

104
Q

chem: acid + metal hydroxide ->

A

salt + water

105
Q

chem: acid + metal carbonate ->

A

salt + water + carbon dioxide

106
Q

chem: what are the 3 ways of detecting the acidity or alkalinity of a substance

A
  • litmus paper
  • universal indicator
  • PH probe
107
Q

chem: what litmus paper is used to determine alkalinity

A

red litmus paper turns blue

108
Q

chem: what litmus paper is used to determine if a substance is acidic

A

blue litmus paper turns red

109
Q

chem: define titration

A

it is a technique that measures the volumes of acid and alkali solutions needed in a neutralization reaction

110
Q

chem: define a strong acid

A

it is an acid that when in water fully ionises, all of the acid breaks up to form H+ ions

111
Q

chem: what is a weak acid

A

it is an acid that when in water does not fully ionise, most are weak

112
Q

chem: what is the equation for fermentation

A

glucse -> ethanol + carbon dioxide

113
Q

chem: what is a limiting reactant and how do you find it

A

it is the reactant that is completely used up first, the reaction stops when this happens, you find it by finding the reactant with the lowest moles

114
Q

chem: if i fill 3 ballons with gas, one with 1 mole methane, one with 1 mole argon and one with 1 mole chlorine, which baloon will be the largest

A

they will all be the same size because at the same temperature and pressure one mole of any gas will have the same volume.

115
Q

chem: for titrations what is the range for concordant results

A

0.1 cm3

116
Q

chem: if a there is 20 cm3 of liquid in my measuring tube and it has an uncertanty of 1 cm3, write lower and upper bounds for the amount of liquid

A

19.5 < l < 20.5

117
Q

chem: Name three factors that make the percentage yield of a reaction less than 100%?

A

reaction is incomplete
waste products
side reactions

118
Q

chem: what makes a chemical cell have more voltage/potential difference

A

more difference in reactivity will result in more voltage

119
Q

chem: what happens to a chemical cell when you change the electrode

A

changing the electrode will change the reactions that happen at each electrode and so change the voltage

120
Q

chem: what makes a chemical cell non - rechargable

A

irreversable chemical reactions take place at the elctrodes, as soon as the one of the reactants has run out electrisity cannot be produced.

121
Q

chem: what makes a chemical cell rechargable

A

connection to an electric current reverses the reactions that occured to produce electrisity and recharges the cell

122
Q

chem: what are fuel cells

A

they produce electrical energy by reacting a fuel (often hydrogen) with oxygen (e.g. from the air), when this happens a current is produced and a current will continue to be produced unitll the fuel runs out.

123
Q

chem: what are the pros of fuel cells

A

they have high efficiency
they can produce less polution
they are reliable as they have no moving parts
they can be compact

124
Q

chem: hydrogen fuel cells vs petrol, which has a higher energy per gram

A

hydrogen fuel cells

125
Q

Chem: if a change of state happens and the temperature increases during the change of state what can we say about the substance

A

It is impure or a mixture

126
Q

Chem: what is Rf in chromatography

A

It is the retention factor, its equation is distance traveled by dye(compound) / distance traveled by solvent

127
Q

Chem: what is chromatography used for

A

It is used to distinguish between pure and impure substances

128
Q

chem: why are small covalent molecules liquids or gasses at room temperature

A
  • when molecules melt or boil it is the intermolecular forces that break
  • these intermolecular forces are weak in simple covalent substances
129
Q

chem: define alloys

A

they are combinations of 2 or more elements when one of them is a metal

130
Q

chem: what is the difference between metals and alloys

A

alloys are:
- stronger than metals
- contain other elements
- harder
- the layers in alloys are distorted

131
Q

chem: what are the 2 types of conductor

A

heat - delocalized electrons can carry heat
electrical

132
Q

chem: what is an allotrope and what is an example of one

A

it is a different form or an element
diamond is an allotrope of carbon

133
Q

chem: what are the properties of diamond

A
  • they are hard, they have lots of covalent bonds
  • covalent bonds, every carbon atom is bonded to 4 others
  • diamond has not delocalized electrons that can conduct a charge
  • high melting and boiling point, it is very hard to break strong covalent bonds, hence high melting and boiling point
134
Q

chem: what are the properties of graphite

A
  • covalent bonds, each carbon atom is bonded to 3 others
  • soft, there are layers to graphene that are able to slide over one another
  • conductivity, each carbon atom forms 3 bonds, there is a delocalized electron for every carbon atom
135
Q

chem: what are the properties of graphene

A
  • conducts, delocalized electron can conduct
  • graphene is light but strong because it is one layer thick
136
Q

chem: what is a fullerine

A

they are allotropes of carbon that take hollow structures

137
Q

chem: what is a spherical fullerene called

A

it is called a buckminsterfullerene

138
Q

chem: what are some uses of buckminsterfullerenes

A

they can be used for:
- catalysts
- lubricants
- as vehicles for transporting drugs into our bodies

139
Q

chem: what are some properties of cylindrical fullerenes

A
  • strength, strong covalent bonds
  • conductivity
140
Q

chem: describe cylindrical fullerenes

A

they are called carbon nanotubes and take the shape of a cylinder, they are often called molecular wires because they have a tiny diameter but are very long

141
Q

chem: what are some uses of cylindrical fullerenes

A
  • electronics
  • nanotechnology
  • for strengthening materials
142
Q

chem: what are clumps of particles

A

matter often ‘clump’ up into small particles, the size of the clump gives it a different name:
- nanoparticles
- fine particles
- coarse particles

143
Q

Chem: why, when tennessine was discovered in 2010, was it not recognised as a new element until 2015

A

Because the discovery of the element must be repruducable

144
Q

Chem. what is the dependent variable

A

The one that the depends on the other variables

145
Q

Chem: how to calculate overall energy change

A

Energy in bonds of reactants - energy in the bonds of products = overall energy change
Energy in - energy out = overall energy change

146
Q

Chem: why do alloys conduct electricity worse than pure metals

A

Because the different elements in the alloy interrupt the lattice structure and make it harder for the electrons to move through the structure

147
Q

Chem: what equation links moles, volume and concentration

A

Conc = moles / volume

148
Q

Chem: explain how, in aluminium, electrons carry a change

A
  • delocalised electrons
  • they can carry a charge
  • they flow through the substance
149
Q

chem: who came up with the plum pudding model, when?

A

JJ thompson, 1897

150
Q

chem: who thought the atom was a nucleus with all of the posotive charge in the center and a cloud of neagtive charge, when

A

Ernest Rutherford, 1909

151
Q

chem: who came up with the idea that electrons were in shells with orbits, when?

A

Niels Bohr, 1913

152
Q

chem: who came up with the idea of protons, when

A

Rutherford, 1919

153
Q

chem: who came up with the idea of neutrons

A

James Chadwick, 1932

154
Q

chem: what are all of the transition elements

A

they are metals

155
Q

chem: what are the properties of the alkali metals

A
  • low dencity
  • relativly low melting point
  • soft, can be cut with a scalpel
  • very reactive
156
Q

chem: what is a giant ionic latice

A

it is an ionic structure with an underined amount of ions

157
Q

chem: what are the properties of giant ionic lattices

A
  • each positive ion is surrounded by a negative ion
  • they are 3d structures
  • very strong forces of attraction between pos and neg ions (electrostatic forces of attraction) which hold the ions in place
  • very high melting and boiling points
158
Q

chem: what are electrostatic forces

A

they are the forces between posotive and negative ions

159
Q

chem: what can ionic compounds do when molten or dissolved, how?

A

they can conduct electrisity, remember that it is the ions that move not the electrons

160
Q

Chem: in diamond, graphite and graphene what are the bonds

A

covalent

161
Q

chem: what is the main property of nanoparticles

A

very high surface are to volume ratio

162
Q

chem: what is the empirical formula

A

The empirical formula of a compound is the simplest, whole number ratio of atoms of each element in a compound,

163
Q

chem: what is an exothermic reaction profile

A
164
Q

chem: what is an endothermic reaction profile

A
165
Q

chem: what is the structure of a hydrogen fuel cell

A
166
Q

chem: what type of equation shows electrons

A

ionic

167
Q

chem: what is the reactivity series

A
168
Q

chem: what is the equation for moles involving Mr

A

Moles = mass / Mr

169
Q

Chem: what are 4 types of Exothermic reactions

A
  • neutralisation
  • combustion
  • oxidation
  • hand warmer
170
Q

Chem: what are the 3 types of endothermic reactions

A
  • thermal decomposition
  • citric acid + baking soda
  • sport injury packs
171
Q

Chem: what are the 2 requirements for a reaction to occur

A
  • collisions
  • activation energy
172
Q

Chem: through bond energy how do you find if a reaction is Exothermic or endothermic

A

You can subtract the bond energy from products and reactants, if the answer is pos then it is endothermic and if the answer is negative then it is Exothermic

173
Q

Chem: how many electrodes are required to create a chemical cell

A

2

174
Q

Chem: what is a battery

A

It is multiple cells joined in series

175
Q

Chem: what are the 2 parts of chemical cells

A

Electrodes and electrolytes

176
Q

Chem: how do you find the voltage of a battery

A

It is the sum of the voltages of the individual cells

177
Q

Chem: what is the reason for a battery not being usable any more

A

Chemicals in the battery running out