whole of chemistry 1 Flashcards
1
Q
define a compound
A
two or more elements chemically bonded together
2
Q
mendeleev
A
he arranged elements by mass, similar patterns and left gaps for unknown elements
3
Q
what do groups show?
A
how many electrons in the final shell
4
Q
what do periods show?
A
how many shells there are
5
Q
where are metals on the periodic table and what do they do?
A
they’re on the left hand side
they lose electrons which gives them a positive charge
6
Q
where are non-metals on the periodic table and what do they do?
A
they’re on the right hand side
they gain electrons giving them negative charge
7
Q
define ionic bonding
A
the transfer of electrons between a metal and non metal
8
Q
what is the structure of an ionic compound?
A
giant lattice structure, high mp/bp, conduct when molten/dissolved as the ions are free to move
9
Q
define covalent bonding
A
the sharing of electrons between two non-metals
10
Q
formula for carbon dioxide
A
CO2
11
Q
formula for water
A
H2O
12
Q
formula for oxygen gas
A
O2
13
Q
formula for hydrogen gas
A
H2
14
Q
formula for nitrogen gas
A
N2
15
Q
formula for ammonia
A
NH3
16
Q
formula for hydrochloric acid
A
HCl
17
Q
formula for sulfuric acid
A
H2SO4
18
Q
characteristics of simple covalent bonds
A
low mp/bp
do not conduct electricity
19
Q
characteristics of giant covalent bonds
A
high mp/bp
do not dissolve
do not conduct electricity
20
Q
structure of diamond
A
made of carbon atoms- each carbon makes 4 bonds
very hard
can be used for cutting tools
21
Q
structure of graphite
A
made of carbon atoms- each carbon makes 3 bonds
soft
conducts electricity
made in sheets
used in pencils
22
Q
structure of fullerene
A
made of carbon atoms- each carbon makes 3 bonds
very hard
can be used as a lubricant
23
Q
define polymer
A
a large molecule made up of repeated subunits known as monomers
24
Q
what happens when polymers with cross links are heated
A
they will stay fixed in place and burn
25
what happens when polymers without cross links are heated
they will melt because they can slide over each other
26
acid + metal —> ___ + ___
acid + metal —> salt + hydrogen
27
define moles
units for the amount of a substance
28
equation for moles
moles = mass/mR
29
what is avagadro’s constant
6 x 10^23
30
equation for concentration
concentration (mol/dm^3) = amount (mol) / volume (dm^3)
31
what are metals made up of?
positive ions in a sea of delocalised electrons allowing them to conduct electricity
32
what is an alloy made up of?
positive ions in a sea of delocalised electrons but also containing a metal or non-metal
they have distorted layers that cannot slide meaning they’re hard
33
what is it called to go from:
solid —> liquid —> gas
solid —> liquid = melting
liquid —> gas = evaporating/boiling
gas —> liquid = condensing
liquid —> solid = freezing
solid —> gas/gas —> solid = sublimation
34
energy from different states
solid —> liquid —> gas = energy in
gas —> liquid —> solid= energy out
35
liquid + liquid —> solid (___)
liquid + liquid —> solid (cloudy)
36
liquid + solid —> gas (___)
liquid + solid —> gas (bubbles)
37
liquid + liquid —> gas (___)
liquid + liquid —> gas (bubbles)
38
equation for Rf
Rf= distance moved by spot / distance moved by solvent
39
equation for atom economy
atom economy= mR of atoms in required products / mR of reactants
40
how to purify water
remove the salt (desalination)
remove dirt/bacteria/unwanted ions
add chlorine/fluorine
41
bond for:
hydrogen + chloride —> hydrogen chloride
H—Cl
42
bond for:
hydrogen (H2)
H—H
43
bond for:
ammonia (NH3)
H — N — H
|
H
44
bond for:
chlorine (Cl2)
Cl—Cl
45
bond for:
methane (CH4)
H
|
H — C — H
|
H
46
bond for:
oxygen (O2)
O = O
47
bond for:
nitrogen (N2)
N ≡ N
48
what does each line on the bonds show?
how many pairs of electrons being shared
49
pH scale: acid
pH of 1-6
H+ hydrogen ions
50
pH scale: neutral
pH of 7
51
pH scale: alkali
pH of 8-14
OH- hydroxide ions
52
what is the neutralisation equation?
H+ + OH- ⇌ H2O
acid + alkali —> salt + water
53
what colour does phenolphthalein go in an alkali and an acid?
acid= colourless
alkali= pink
54
what colour does methyl orange go in an acid and alkali?
acid= red
alkali= yellow
55
which type of acids fully dissociate?
strong acids
56
which acids partially dissociate?
weak acids
57
acid + metal —> ?
acid + metal —> salt + hydrogen
58
acid + metal oxide —> ?
acid + metal oxide —> salt + water
59
acid + metal hydroxide —> ?
acid + metal hydroxide —> salt + water
60
acid + metal base —> ?
acid + metal base —> salt + water
61
acid + metal carbonate —> ?
acid + metal carbonate —> salt + water + carbon dioxide
62
what happens when hydrogen gas is present?
squeaky pop
63
what happens when oxygen gas is present?
relight glowing splint
64
what happens when carbon dioxide gas is present?
turns limewater cloudy
65
what happens when chlorine gas is present?
bleach damp litmus paper
66
OILRIG
Oxidation
Is
Loss
Reduction
Is
Gain
67
PANIC
Positive
Anode
Negative
Is
Cathode
68
Reactivity Series
Potassium
Sodium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Tin
Lead
Hydrogen
Copper
Silver
Gold
69
calculation for moles
mols= concentration x volume
OR
mols= mass/mR
70
calculation for percentage yield
percentage yield= actual yield/ theoretical yield
71
in electrolysis what does sodium chloride produce?
H2
Cl2
NaOH
72
in electrolysis what does sodium sulfate produce?
H2
O2
73
in electrolysis what does copper chloride produce?
Cu
Cl2
74
in electrolysis what does copper sulfate produce?
Cu
O2
75
process of making a pure salt:
heat sulfuric acid
stir in copper oxide until it is in excess
let it cool
filter solution to remove excess copper oxide
evaporate away the liquid
76
titration method:
• pipette 250cm3 of alkali into a conical flask, add a phenolphthalein indicator
• fill a burette with an acid of known concentration
• take initial reading on burette and record it
• while swirling the flask, use the tap to slowly add the acid to the alkali
• when it changes from pick to colourless stop adding the acid
• record final volume in the burette
• repeat until titres are within 0.05cm3
77
properties of transition metals:
• hard
• shiny
• conductors of electricity
78
equation for rusting:
iron + oxygen + water —> iron oxide
79
how do you stop rusting?
- use a sacrificial metal
- exclusion of oxygen
- exclusion of water
80
titration calculations:
• calculate the number of mols of acid used
• use this to find num of H+ ions involved in reaction, this is equal to the number of OH- ions
• calculate num of moles of alkali used
• calculate the concentration of alkali
81
why are alloys stronger than metals?
they contain metals in different sizes and an irregular strangely meaning they can’t slide over each other easily
82
what are the strengths and weaknesses for fuel cells?
strengths:
- water is the only product
- less maintenance required
- quieter than petrol/diesel engines
weaknesses:
- H2 needs to be stored in a tank
- constantly needs to be supplied with fuel
- H2 is produced by steam
83
what do fertilisers promote and what do they replace?
they promote plant growth and they replace mineral ions
84
what are the two types of fertilisers and what are they both also known as?
- ammonium nitrate
- ammonium sulfate
these are both salts
85
formula for nitric acid:
HNO3
86
what is the haber process?
where ammonia is formed from nitrogen
87
what is the equation for the haber process?
N2 + (3)H2 ⇌ (2)NH3
88
what are the conditions that the haber process takes place is?
450 degrees
pressure of 200 atmospheres
iron catalyst
89
compare the making of ammonium sulfate in an industry and lab
industry:
- large scale
- continuous
- the method is in several stages
lab:
- small scale
- only create a batch at a time
- the method used is titration
90
define dynamic equilibrium
when the forwards and backwards reaction are happing at the same rate
91
define reversible reactions
where the forwards and backwards reaction happen at the same time, not the same rate
92
which 3 things can shift the equilibrium?
- temperature
- pressure
- concentration
93
how does pressure affect the equilibrium?
higher pressure means that the equilibrium moves to the side with fewer molecules (the number infront of the symbol when balancing)
94
how does concentration affect the equilibrium?
higher concentration of reactants means you are making more products as the equilibrium moves to that side
95
how does temperature affect the equilibrium?
higher temperatures means it moves to the endothermic direction
lower temperatures means it moves to the exothermic direction
96
what is the equation for volume of gas?
volume of gas = amount of gas x molar volume (always 24dm3)
97
what are the charges and masses of protons, neutrons and electrons?
proton: charge= +1 mass= 1
neutron: charge= 0 mass= 1
electron: charge= -1 mass= 1/1836
98
how do you calculate r.a.m?
(mass of isotope x %) + (mass of isotope x %) + (mass of isotope x %) / 100
99
what colour does litmus go in an alkali and an acid?
alkali= blue
acid= red
100
Investigate the change in pH on adding powdered calcium hydroxide or calcium oxide to a fixed volume of dilute hydrochloric acid
- add dilute HCl to the beaker and measure pH
- add weighed mass of calcium hydroxide and stir then record pH
- keep adding weighed masses of calcium hydroxide until there is no more
change to the pH
101
what does it mean if something is concentrated?
large amount of substance in the given volume
102
what does it mean if something is dilute?
lesser amount of substance in a given volume of a solution
103
what does it mean if something is a strong acid?
it fully dissociates in an aqueous solution releasing more H+ ions
104
what does it mean if something is a weak acid?
it partially dissociates in an aqueous solution releasing less H+ ions
105
what is the definition of electrolysis?
using electricity to split a substance
106
in electrolysis, where do the positively charged ions (cations) move?
to the negative electrode (cathode)
107
in electrolysis, where do the negatively charged ions (anions) move?
to the positive electrode (anode)
108
what happens at the anode and what happens at the cathode?
anode= oxidation
cathode= reduction
109
draw and label the diagram for electrolysis
110
state the reactivity series
potassium
sodium
calcium
magnesium
aluminium
carbon
zinc
iron
tin
led
hydrogen
copper
silver
gold
111
how do things above carbon in the reactivity series get extracted?
electrolysis
112
how do things below carbon in the reactivity series get extracted?
displacement reaction with carbon
113
how do you extract silver and gold?
mining
114
what is an ore?
a mineral that can be extracted
115
give 5 reasons why we should recycle metals?
- burning less fossil fuels
- less space needed for landfill sites
- doesn’t destroy habitats
- saves energy
- saves money
116
what are the 4 stages of a life cycle assessment?
- making the material
- manufacturing the product
- using the product
- disposing the product
