8 acids and bases Flashcards
1
Q
metal oxides are
A
bases
2
Q
non metal oxides are
A
acids
3
Q
precision -
A
how close results are to eachother
4
Q
accuracy -
A
how close results are to the true value
5
Q
which acids are monoproteoic
A
HCl
HNO3
CH3COOH
6
Q
which acid is duoproteoic
A
H2SO4
7
Q
whicha cid is triproteoic
A
H3PO4
8
Q
which substances do you divide into ions in writing ionic equations from balanced chemical equation
A
ioniclly bonded ones
9
Q
bronsted lowry acid
A
donates proton
10
Q
bronsted lowry base
A
proton acceptor
11
Q
amphiprotic means
A
a species able to act as a bronsted lowry base or acid
12
Q
amphoteric
A
a species able to act as a base or acid
13
Q
what defines pH
A
[H+]
14
Q
pH =
A
-log[H+]
15
Q
how to work out pH from [H+]
A
-log[H+]
16
Q
how to work out [H+]
A
10 to the power of -pH
aka shift log -
17
Q
how can you calculate a new conc when the old one has been diluted
A
conc1 x vol1 = conc2 x vol2
18
Q
Kw =
A
[H+] [OH-] = 1 x 10^ -14
19
Q
when would you use Kw
A
when you need to calculate pH and only have the conc of [OH-] ions
work out [H+] using equation and then -log it
20
Q
differentiate between strong and weak acids
A
strong acids fully ionise in water
weak acids only partially ionise in water
21
Q
what is the electrical conductivity of a strong acid
A
high
22
Q
what is the electrical conductivity of a weak acid
A
low
23
Q
relative reaction of a strong acid with magnesium and calcium carbonate
A
fast
24
Q
relative reaction of a weak acid with magnesium and calcium carbonate
A
slow
25
what is the electrical conductivity of a strong alkali
high
26
what is the electrical conductivity of a weak alkali
low
27
describe the strengths within conjugate acid pairs
strong acids have relatively weak conjugate bases and weak acids have relatively strong conjugate bases
28
problems with combustion
incomplete combustion (formation of toxic gas CO)
respiratory problems with carbon
makes buildings black
complete combustion forming CO2
sulfur dioxide formation from coal (sulphur impurities removed)
N2 + O2 --> 2NO at high car engine temps
29
problems with the CO2 formed from complete combustion
greenhouse gas --> global warming.
| reduce this by burning less fossil fuels
30
CO formed by incomplete combustion results in...
toxic gas that can cause health problems.
| fix by ensuring a good supply of air/oxygen when burned
31
problems with the C formed by incomplete combusiton
blackens building
global dimming
fix by ensuring a good supply of air/oxygen when burned
32
problems with the sulfur dioxide fomred by combustion of sulfur
acid rain
| fix by removing s from fume before burning or removing SO2 from fumes after burning (flue gas desulfurization)
33
problems with nitrogen oxides formed by the reacton of N2 in air with O2 in air at very high temperatures (often engines or furnaces)
acid rain.
| fix by using a catalytic converter in cars
34
give the equation of the reaction carried out by a catalytic converter
NO + CO --> 1/2N2 + CO2
35
why is rain naturally acidic
becase of the dissolved CO2 .
| has a pH of 5.6
36
pH of acid deposition
below 5.6
37
when is acid deposition formed
when nitrogen or sulfur oxides dissolve in water to form HNO3, HNO2, H2SO4 and H2SO3
38
Describe what happens when acid droplets are present in the atmosphere
They can combine with clouds or be washed out of the air with rain to fall as acid rain
39
Effects of acid rain
Enters leaves and damages them
Acid gases damage stonework and metals then changes the biology of lakes acid lakes often very clear as they lack the minute plants and animals
On Sandy soils acid rain dissolves aluminium ions which can reduce tree growth by damaging root hairs
Aluminium ions can kill fish and destroy fish eggs
40
Natural rainwater pH
5.6 because dissolved CO2 is slightly acidic
41
Give the reaction equation for carbon dioxide and water
CO2 + H2O
42
Where is battery acid on the pH scale
1&2
43
What is acid rain pH
3,4,5.5
44
What is normal rain to pure water on the pH scale
5,6,7
45
Whar is ocean water pH
8
46
What is liquid drain cleaner pH
9 upwards
47
How can nitrogen monoxide be formed
Lightning or internal combustion engines
48
Give the equation to form NO
N2 + O2 --> 2NO
49
Give the equation to form 2NO2
2NO + O2 --> 2NO2
50
How is nitrous acid formed (4HNO2)
4NO + 2H2O + O2 --> 4HNO2
51
Give the equation resulting in the formation of HNO2
2NO2 + H2O --> HNO3 + HNO2
52
Give the equation resulting in nitric acid (4NHO3)
4NO2 + 2H2O + O2 --> 4HNO3
53
How is sulphur dioxide produced
Released in volcanic eruptions
| When coal and oil are burned in power stations
54
How is H2SO3 formed
SO2 + H2O --> H2SO3
55
How is 2SO3 formed (give equation)
2SO2 + O2 --> 2SO3
56
How is sulfric acid (H2SO4) formed (give equation)
SO3 + H2O --> H2SO4
57
What is dry deposition
Acid deposition in the form of acidic particles and gases
58
pH =
- log [H+]
59
pOH =
-log [OH]
60
Kw =
[H+] [OH-]
61
pH + pOH =
14
62
A Brønsted–Lowry acid is
a proton/H+ donor
63
a Brønsted–Lowry base is
a proton/H+ acceptor
64
An amphiprotic species is able to act as
a Brønsted–Lowry acid and a Brønsted–Lowry base depending on what it is reacting with.
65
Benzoic acid
C6H5COOH (s)
66
Phosphoric acid
H3PO4 (aq)
67
Carbonic acid
H2CO3 (aq)
68
Ethanoic acid
CH3COOH (aq)
69
what determines whether an acid is monoprotic, diprotic or tripotic
number of hydrogen ions or protons
70
Ammonia
NH3
71
Ethanamine
CH3CH2NH2 (g)
72
what does a conjugate acid base differ by
a proton (H+)
73
examples of amphiprotic species
Hydrogen carbonate ion HCO3−
Hydrogen sulfate ion HSO4−
Dihydrogen phosphate H2PO4−
Hydrogen phosphate HPO42−
74
metal + acid →
salt + hydrogen
75
what are alkalis
soluble bases
76
metal oxide + acid →
salt and water
77
metal hydroxide + acid →
salt and water
78
metal carbonate + acid →
salt + water + carbon dioxide
79
metal hydrogencarbonate + acid →
salt + water + carbon dioxide
80
acid + base (or alkali) →
salt + water
81
what type of reaction is acid and base
exothermic. this is known as the enthalpy change of neutrlaistion
82
the higher the concentration of H+ ions in solution,
the lower the pH scale
83
describe the change in litmus paper of an acidic solution
blue litmus changes to red
84
describe the change in litmus paper in an acidic solution
blue litmus changes to red
85
colour oflitmus in acid
red
86
colour of litmus in alkali
blue
87
colour of methyl orange in acid
red
88
colour of methyl orange in alkali
yellow
89
colour of Phenolphthalein in acid
colourless
90
colour of Phenolphthalein in alkali
pink/purple
91
if water cannot conduct electricity very well, it must have
a low concentration of mobile ions responsible for the electrical conductivity of solutions
92
what is it calle when water molecules dissociate
auto-ionisation of water
93
what is the ionic product of water (Kw)
the product of the [H+] and [OH-] in water at a particular temperature.
94
uses of sulfuric acid
fertilisers,
paints and pigments,
soaps and detergents,
fibres and dyes,
95
what does the srength of acids and bases depend on
their degree of dissociation or ionisation in aqueous solution
96
strong acids do what in aqueous solution
completely dissociate or ionise
97
weak acids do what in aquous solution
partially dissociate or ionise
98
what does dissociate mean
break apart an ionic compound into its constituent ions
99
For a strong acid, the concentration of H+ ions, [H+], is equal to
the initial concentration of the strong acid.
100
what does HCL dissociate to give
H+ (aq) + Cl– (aq)
101
what does H2SO4 dissociate to give
H+ (aq) + HSO4– (aq)
102
what does HNO3 dissociate to give
H+ (aq) + NO3– (aq)
103
are organic acids usually strong or weak
usually weak (Kc small)
104
do weak acids have small or large Kc's
small
105
what does NaOH dissociate to give
Na+ (aq) + OH– (aq)
106
what does KOH dissociate to give
K+ (aq) + OH– (aq)
107
what does Ba(OH)2 dissociate to give
Ba2+ (aq) + 2OH– (aq)
108
For a strong base, the concentration of OH– ions, [OH–], is equal to
the initial concentration of the strong base.
109
which bases are weak
all of them except for the hydroxides of groups 1 and 2
110
which bases are strong
hydroxides of groups 1 and 2
111
equimolar solutions
same concentrations
112
elec conductitvity of strong acids
high
113
elec conductitvity of weak acids
low
114
relative rate of reaction with magneium and strong acid
fast
115
relative rate of reaction with magneium and weak acid
slow
116
relative rate of reaction with calcium carbonate and a strong acid
fast
117
relative rate of reaction with calcium carbonate and a weak acid
slow
118
if one part of the conjugate acid base pair is weak the othe rpart is
strong. one will be weak and one will be strong, or both will be moderate
119
what is hydrodesulfurisation
a pre-combustion method of reducing sulfur dioxide emissions
120
State the name of the conjugate base of water. Give the name of the ion, not the formula.
hydroxide
121
how come you can use a conductivity metre in ionic solutions but not covalent
Since aqueous ionic compounds involve the dissociation of ions into their solvent, water, the ions will move around as individual ions. covalent compounds do not dissociate into ions so you cannot measure them using a conductivity metre
122
outline a precombustion method
Hydrodesulfurisation is a pre-combustion method by which the sulfur is removed from refined petroleum products such as gasoline, jet fuel, kerosene and diesel fuel before combustion. This process takes place at high temperatures and pressures (300-400 oC at pressures of between 300000 - 1300000 Pa) in the presence of a catalyst. The sulfur is removed from the product in the form of hydrogen sulfide (H2S).
123
outline a post combustion method
A post-combustion method utilised in power stations is flue gas desulfurisation. The levels of sulfur dioxide emissions in the flue gases can be reduced by passing them into a flue gas desulfurisation tower, also known as a 'scrubber' In the scrubbing tower, the gases are passed through a sprayed aqueous suspension of calcium carbonate and calcium oxide. The product is calcium sulfite (sulfate(IV)) which is further oxidised to produce calcium sulfate.
124
give the equation to show how nitrogen oxide (NO) forms nitric acid, HNO3, and nitrous acid, HNO2
2NO2 + H2O --> HNO3 + HNO2
125
give the equations to show how sulfur dioxide, SO2, forms sulfuric acid (H2SO4) and sulphurous acid (H2SO3)
SO2 + H2O --> H2SO3
| SO2 + O2 +H 2O → H 2SO4
126
describe and explain how acid rain affects the growth of trees
acid rain enters the leaves and damages them
| on some sandy soils, acid rain dissolves aluminium ions which can reduce the tree growth by damaging root hairs
127
acid rain formula
HNO3
| H2SO4
128
what does calcium oxide dissolve in water to form
calcium hydroxide
