Module 6: Acids and Bases Reactions Flashcards
(113 cards)
1
Q
Hydrochloric acid
A
HCl
2
Q
Sulphuric acid
A
H2SO4
3
Q
Nitric acid
A
HNO3
4
Q
Ethanoic/acetic acid
A
CH3COOH
5
Q
Carbonic acid
A
H2CO3
6
Q
Phosphoric acid
A
H3PO4
7
Q
Citric acid
A
C6H8O7
8
Q
Ascorbic acid (vitamin c)
A
C8H8O6
9
Q
Sodium hydroxide
A
NaOH
10
Q
Ammonia
A
NH3
11
Q
Calcium hydroxide
A
Ca(OH)2
12
Q
Magnesium hydroxide
A
Mg(OH)2
13
Q
Sodium carbonate
A
Na2CO3
14
Q
How do you know if something is an acid?
A
It has a H+
15
Q
How do you know if something is a base?
A
It has OH- or O2-
16
Q
What are the 5 properties of acids?
A
- Sour taste
- Sting or burn the skin
- Are electrolytes
- Turn litmus paper red
- PH less than 7
17
Q
What are the 5 properties of bases?
A
- Bitter taste
- Soapy or caustic feel
- Are electrolytes
- Turn litmus paper blue
- PH greater than 7
18
Q
What are monoprotic acids?
A
Acids capable of donating one proton only
19
Q
What are diprotic acids?
A
Acids capable of donating two protons
21
Q
What are the 3 strong acids that need to be memorised?
A
HCl, H2SO4, HNO3
21
Q
What are weak acids?
A
All other acids which aren’t HCl, H2SO4 or HNO3
22
Q
What are strong bases?
A
Any which have hydroxides in them
23
Q
What are weak bases?
A
Any which don’t have hydroxides in them
24
Q
What type of arrow is used when there is a strong acid or base in a reaction?
A
→
25
What type of arrow is used if both the acid and the base are weak?
⇌
26
Do acids lose or gain a proton to form its conjugate base?
Lose a proton
27
Do bases lose or gain a proton to form its conjugate acid?
Gain a proton
28
What is the acid metal hydroxide word equation?
Acid + Metal Hydroxide → Salt + Water
29
What is the acid metal word equation?
Acid + Metal → Salt + Hydrogen
30
What is the acid and metal carbonate word equation?
Acid + Metal Carbonate → Salt + CO2 + Water
31
How did Boyle describe acids and bases?
Described acids and bases by there property
32
What did Boyle notice about acids and bases?
Bases could reverse colour change of indicators mixed with acids
33
What did Lavoisier conclude about acids?
Acids contain oxygen
34
Why wasn't Lavoisier's conclusion that acids contain oxygen correct?
HCl and HCN are also acids
35
What did Davy conclude about about acids?
All known acids contain hydrogen
36
What did Davy conclude about bases?
Metal compounds with oxygen are bases
37
What is an Arrhenius acid?
A molecule that contains hydrogen and can produce H+ ions in water
38
What is an Arrhenius base?
A molecule that dissociates in water to produce OH-
39
What did Arrhenius suggest about mixing bases and acids?
That they will produce water
40
What were the four main limitations of Arrhenius' idea?
- Could not explain NH3 which has no OH- but is a base
- Could only be applied to aqueous solutions
- Did not explain strength of acids and bases
- Could not explain why some reactions did not form neutral solutions
41
What is a Bronsted - Lowry acid?
A molecule which is a proton (H+) donor
42
What is a Bronsted - Lowry base?
A molecule which is a proton (H+) acceptor
43
What was an advantage of the Bronsted - Lowry theory?
Reactions were no longer limited to aqueous solutions
44
What were four disadvantages of the Bronsted - Lowry theory?
- A proton that can be transferd must be present for a substance to be an acid or a base
- Model requires a solvent
- Could not explain reaction where no protons are involved
- Could not explain reactions between acidic oxides and basic oxides
45
What is a Lewis acid?
A molecule that is an electron pair receptor
46
What is a Lewis base?
A molecule that is an electron pair donor
47
What were two advantages of the Lewis theory?
- Broader definition to explain more acid and base reactions
Does not require a proton or a solvent
48
Do acids lose or gain a proton to form a conjugate base?
Lose a H+
49
Do bases lose or gain a proton to form a conjugate acid?
Gain a H+
50
What is an amphiprotic substance?
A substance that can either donate or accept protons
51
What are two examples of amphiprotic substances?
H2O
H2PO4 -
52
What is a monoprotic acid?
Can only donate one proton
53
What is a diprotic acid?
Can donate two protons
54
What is a triprotic acid?
Can donate three protons
55
What is a polyprotic acid?
Can donate more than one proton
56
What makes an acid strong?
Readily dissociates in water and donate protons to form hydronium
57
What is ionisation?
When a free H+ combines with water to form H3O+
58
What makes an acid weak?
Does not dissociate readily and reacts only partially with water
59
What makes a base strong?
O2 or OH- readily dissociate in water to make hydroxide ions which can accept protons
60
What makes a base weak?
Only have a small amount of molecules that have accepted a proton to form ions
61
How is the strength of a base or acid impact the conjugate base or acid?
The stronger the acid or base the weaker the conjugate base or acid will be
62
What does strength of an acid/base relate to?
Relates to its ability to dissociate
63
What does concentration of an acid/base show?
The number of mol/L
64
What does Kw stand for?
Ionic product constant of water
65
What can change the Kw?
Slightly changes with temperature or pressure
66
What is the Kw at normal (25C) of H3O+?
1 x 10^-7 mol/L
67
What is the Kw at normal (25C) of OH-?
1 x 10^-7 mol/L
68
What is the Kw of water at normal (25C)?
1 x 10^-14 mol/L
69
What is the pH scale?
Is a measure of acidity related to the concentration of hyrdonium ions
70
What are the formulas for pH and pOH?
pH = -log[H3O+]
pOH = -log[OH-]
71
What are the formulas to find the concentration of H3O+ and OH- from pH and pOH?
[H3O+] = 10^-pH
[OH-] = 10^-pOH
72
What does pH + pOH = at normal (25C)
14
73
What is a standard solution?
A solution with an accuratly known concentration
74
What is the standard solution called in a titration?
Titrant
75
How is a standard solution made?
By dissolving a primary standard in a known volume of water
76
What are 7 characteristics of a primary standard?
1. Is a solid
2. Easily obtained in pure form
3. Stable and easy to store
4. Has a high molar mass
5. Has high solubility in water
6. Should react instantaneously
7. Should be inexpensive
77
What is a titration?
A method to determine the concentration of an unknown solution
78
What is the analyte?
Is the solution of unknown concentration
79
What is the analyte usually put in?
A conical flask
80
What is the titrant usually put in?
A burette
81
What is the titre?
The minimum quantity of a solution required to complete a titration
82
What is an aliquot?
A small sample of analyte usually 25mL
83
What is the endpoint of a titration?
The point at which the indicator changes colour
84
What should the burette be rinsed with?
With the titrant
85
What should the pipette be rinsed with?
With the analyte
86
What should the conical flask be rinsed with?
With distilled water
87
What should the volumetric flask be rinsed with?
With distilled water
88
What is the chemical representation of the indicator in a chemical equation?
HIn
89
What is the pH of a strong acid + strong base?
7
90
What is the pH of a weak acid + weak base?
7
91
What is the pH of a strong acid + weak base?
pH < 7
92
What is the pH of a weak acid + strong base?
pH > 7
93
What are the three indicators usually used?
Methyl orange
Bromothymol blue
Phenolphthalein
94
What is the pH colour change range of methyl orange?
3.2 - 4.4
95
What colour is methyl orange in acid, base and neutral?
Acid: Red
Neutral: Orange
Base: Yellow
96
What is the pH colour change range of bromothymol blue?
6.0 - 7.6
97
What colour is bromothymol blue in acid, base and neutral?
Acid: Yellow
Neutral: Green
Base: Blue
98
What is the pH colour change range of phenolphthalein?
8.3 - 10.0
99
What colour is phenolphthalein in acid, base and neutral?
Acid: Colourless
Neutral: Light pink
Base: Pink
100
How does pKa influence PH?
The lower the pKa the lower the PH
101
What does pKa determine?
The strength of an acid
102
How is pKa calculated?
-log Ka
103
How do you calculate Ka from a known pH?
Use a rice table and make the change x and then calculate [H3O+] using the given pH
104
What is the formula for Ka?
PORK but only with aqueous solution
105
What happens to the pH when an acid is diluted?
pH increases
106
What happens to the pH when a base is diluted?
pH decreases
107
What determines the pH of a buffer solution?
Determined by the pKa of the acid and the relative concentration of the acid and its conjugate base
108
What flask is used when creating a standard solution?
Volumetric flask
109
How do you identify conjugate acid/base pairs?
There should only be a difference of H+
110
How do Aboriginal and Torres Strait Islander Peoples use their knowledge of acids and bases?
They use it for both medicinal and nutritional purposes
111
What is an example of how Aboriginal and Torres Strait Islanders used their knowledge of acids and bases for nutritional purposes?
They ate Quandong a plant that contains high levels of nutritional vitamin C
112
What is an example of how Aboriginal and Torres Strait Islanders used their knowledge of acids and bases for medicinal purposes?
They used clays which are alkaline to treat stomach issues as basic clays would neutralise the stomach acid
113
What is the equivalent point?
When the reaction has reached a specific stoichiometric ratio of reactants. The number of H+ is equal to the number of OH-
