Acids, Bases and Salts Flashcards
(106 cards)
1
Q
Indicators
A
Substances which indicate whether compound is acidic or basic by change in colour
2
Q
Natural Indicators
A
red cabbage extract, turmeric, hydrangea, litmus
3
Q
Artificial Indicators
A
Mehtyl Orange, Phenopthalein
4
Q
TURMERIC
A
yellow in color, remains yellow in acidic soln, turns red in basic soln
5
Q
HYDRANGEA
A
blue in color, remains blue in acidic soln, turn pink in basic soln
6
Q
METHYL ORANGE
A
red color in acidic soln, yellow color in basic soln
7
Q
PHENOPTHALIEN
A
colorless, remains colorless in acidic soln, turns pink in basic soln
8
Q
RED CABBAGE EXTRACT
A
red in color, remains red in acidic soln, turns green in basic soln
9
Q
LITMUS
A
base- turns red litmus blue
acid- turns blue litmus red
10
Q
OLFACTORY INDICATORS
A
indicate whether substance is acidic or basic in nature by changing odor or smell
11
Q
VANILLA EXTRACT
A
characteristic smell remains as it is in acidic soln but cannot be detected in basic soln
12
Q
Onion
A
characteristic smell remains as it is in acidic soln but cannot be detected in basic soln
13
Q
EXAMPLES of OLFACTORY INDICATORS
A
vanilla extract, onion
14
Q
ACIDS
A
sour in taste, conduct electricity
15
Q
ORGANIC ACIDS
A
naturally occuring, weak in nature
16
Q
EXAMPLES OF ORGANIC ACIDS (6)
A
Lactic Acid, Tartaric Acid, Oxalic Acid, Methanoic/formic, Acetic Acid, Citric Acid
17
Q
LACTIC ACID
A
SOUR MILK/CURD
18
Q
TARTARIC ACID
A
TAMARIND, UNRIPE GRAPES
19
Q
OXALIC ACID
A
TOMATOES
20
Q
methanoic acid is also known as
A
formic acid
21
Q
Methanoic Acid
A
Ant’s sting, nettle leave sting
22
Q
Citric Acid
A
citrus fruits like lemon, lime
23
Q
Acetic Acid
A
Vinegar
24
Q
MINERAL ACIDS
A
prepared from minerals of earth, man made, generally strong in nature
25
which mineral acid is not strong in nature
Carbonic acid (H2CO3)
26
three most used mineral acids
Sulphuric, Hydrochloric and Nitric
27
Acetic acid (in form of vinegar) is used in?
pickles, ketchup
28
Tartaric Acid is used in making
baking powder
29
carbonic acid is used in making
fizzy drinks
30
why should water be added gradually while diluting acid?
diluting acid is highly exothermic process--> lot of heat is produced
if water is added at once, large amount of heat would be evolved which would convert some of the water to steam, this might lead to acid splashing and causing burns
31
when acids react with metal
hydrogen gas is formed along with salt
32
example of metal reacting with acid
zinc + sulphuric acid ---> zinc sulphate + hydrogen
| Zn+H2SO4 ---> ZnSO4+H2
33
why should food not be stored in metal containers?
because acid in food will react with metal to form harmful metal compounds
34
acid react with metal carbonate/hydrogen carbonate
to form salt, CO2, H2O
35
example of metal carbonate reacting with acid
sodium carbonate + hydrochloric acid---> sodium chloride + carbon dioxide+ water
Na2CO3 + 2HCl ---> 2NaCl+ CO2+ H2O
36
metal carbonate/hydrogen carbonate + HCl (hydrochloric)
metal chloride+ CO2 + H2O
37
metal carbonate/hydrogen carbonate +H2SO4 (sulphuric)
metal sulphate + CO2 + H2O
38
example of metal hydrogen carbonate reacting with acid
sodium hydrogen carbonate + hydrochloric acid --> sodium chloride+ carbon dioxide + water
NaHCO3+HCl---> NaCl+CO2+H2O
39
lime water and carbon dioxide
Ca(OH)2 + CO2 ---> CaCO3 + H2O
| calcium hydroxide + carbon dioxide + calcium carbonate + water
40
lime water is
calcium hydroxide, Ca(OH)2
41
quicklime is
CaO, calcium oxide
42
slaked lime
Ca(OH)2
43
what can be observed when CO2 passes through lime water
lime water turns milky due to formation of white precipitate (CaCO3)
44
what can be observed when *excess* CO2 passes through
when excess CO2 is passed, white precipitate (CaCO3) dissolves due to formation of calcium hydrogen carbonate and solution becomes clear
CaCO3+CO2+H20---> Ca(HCO3)2
45
different forms of calcium carbonate (CaCO3)
egg shells, chalk, limestone, marble
46
Acid react with base
to form salt and water, neutralization reaction
47
example of acid reacting with base
NaOH (aq) +HCl (aq) ---> NaCl (aq) +H2O (l)
| ]sodium hydroxide + hydrochloric acid --> sodium chloride + water
48
acid react with metal oxide/hydroxide
to form salt and water
49
example of acid reacting with metal oxide
CuO (s) + 2HCl (aq)----> CuCl2 (aq) +H2O (l)
50
what can be observed when copper oxide reacts with hydrochloric acid
change in color from black to blue-green
| this reaction shows basic nature of metal oxide
51
Acids and H+ ions
acids disassociate in water to produce H+ ions
52
are all compounds having hydrogen acidic?
no because some compounds (like glucose) contain hydrogen but do not disassociate in water to form H+ ions
53
why do aqueous acids conduct electricity
aqueous acids conduct electricity because of charged particles (ions) present in them
54
why does rain water conduct electricity but distilled water doesn't?
rain water dissolves with CO2 which is an acidic gas while falling through atmosphere to form carbonic acid (H2CO3). Due to presence of acid, electricity is conducted by rain water. Rain water also dissolves with other acidic gases like SO2, NO2 etc to form acid
55
do acids show acidic behavior in absence of water?
no, because in absence of water acids cannot disassociate into H+ ions
56
Strong acids
completely ionize in water to produce large amount of H+ ions
they react rapidly and are strong electrolytes due to large amount of ions
57
what happens to H+ ions in water
H+ ions attach to polar water molecules to form hydronium ions
H+ ions + H2O---> H3O+ ions
58
Weak Acids
partially ionize in water and produce small amount of H+ ions, react slowly and low electrical conductivity
59
Example of strong acid
H2SO4 (sulphuric), HNO3 (Nitric)
60
Example of weak acid
CH3COOH
61
⇌ what does this double arrow indicate in a chem eqn
indicates partial ionization
62
USES of sulphuric acid (9)
manufacture of fertilizers ( ammonia sulphate ), paints, dyes, chemicals, plastics, synthetic fibres, detergents, explosives, car batteries
63
uses of nitric acid (4)
fertilizers (like ammonium nitrate), explosives ( TriNitro Toluene), dyes and plastic
64
Uses of hydrochloric acid (5)
removing oxide film from steel objects
| removing 'scale' from inside boilers, used in textile, food and leather industry
65
ALKALI
water soluble bases
66
examples of alkali
KOH, NH4OH, NaOH, Ca(OH)2, Mg(OH)2
67
why are alkali more useful than bases
most chemical reactions take place in water, this is why alkali are more useful
68
Bases and OH- ions
bases disassociate in water to form OH- ions
69
Strong Bases
completely ionise in water and produce large amount og OH- ions
70
Weak Bases
partially ionize in water and produce small amount of OH- ions
71
Examples of strong bases
NaOH, KOH
72
Examples of weak bases
NH4OH, Ca(OH)2, Mg(OH)2
73
bases react with metal
for H2 gas
| base + metal ---> salt + H2
74
example of metal reacting with base
sodium hydroxide + zinc ---> sodium zincate + hydrogen
| 2NaOH (aq) + Zn(s) --> Na2ZnO2(aq) +H2 (g)
75
base react with acid
to form salt and water
76
example of base reacting with acid
2NaOH+ H2SO4 ---> Na2SO4 + 2H2O
| sodium hydroxide + sulphuric acid ---> sodium sulphate + water
77
Neutralization reaction in terms of ions
H+ (aq) + OH- (aq) ----> H20 (l)
| H+ ion from acid and OH- ion from base
78
Base react with non metal oxide
to form salt and water
79
example of base + non metal oxide
Ca(OH)2+ CO2 ----> CaCO3 +H2O
80
non metal oxides are ________ in nature
acidic
81
use of sodium hydroxide
soap, paper, rayon (synthetic fibre)
82
use of slaked lime
bleaching powder
83
use of magnesium hydroxide
antacid
84
use of sodium carbonate
washing soda, softening hard water
85
use of sodium hydrogen carbonate
baking soda, making baking powder, antacid, soda-acid fire extinguisher
86
when and who devised pH scale
1909, Sorenson
87
what is pH scale
it is a scale that represents strength of acid and bases through concentration of H+ ions present
pH scale is inversely proportionate to concentration of H+ ions
88
what is pH level of neutral substances
pH level of neutral substances is exactly 7
89
pH level of acid?
acidic soln have pH less than 7
strong acid have pH 0 to 3
weak acid have pH 4 to 6
90
pH level of bases?
more than 7
weak base have pH 8 to 10
strong base have pH 11 to 14
91
Universal Indicator
mixture of many different indicators give different colors at different pH value, They indicate strength of acidic/basic solution
92
what are different colors at different concentration of H+ ion in universal indicator
```
strong acid---> red tones
weak acid ---> orange tones
neutral --> green
weak base --> blue tones
strong base ---> violet tones
```
93
ACIDITY and its remedy
when excess of HCl is produced, it leads to indigestion
| REMEDY - antacid, an antacid can neutralize excess acid and give relief
94
Antacid and their examples
mild bases that dont have any toxic effect on body
examples- Mg(OH)2 - milk of magnesia/ magnesium hydroxide
NaHCO3 - sodium hydrogencarbonate
95
Tooth Decay
bacteria in mouth break down sugar to form acid, when pH of acid falls below 5.6 it becomes strong enough to corrode enamel of teeth
96
how to prevent tooth decay
toothpastes are basic in nature (generally have pH of 8) and they neutralize excess acid, we should clean our teeth with toothpaste regularly
eat less sugary food
97
Plant growth and soil pH
plant grow best when pH of soil is around 7
98
how can we treat soil that is too acidic
CaO (quicklime), Ca(OH)2 (lime water), CaCO3 (chalk) can be used to treat acidic soil as they are basic in nature and can neutralize excess acid
99
how can we treat soil that is too basic
decaying organic matter (manure/compost)
100
how does pH level affect aquatic animals
when rain water has pH of 5.6, it is considered acidic . Too much acid rain can lower pH level of lakes/rivers. Aquatic animals can only survive within narrow range of pH change, this is why, when lakes become too acidic, aquatic animals die
101
how to prevent death of aquatic animals (caused by high acidity of lake)?
CaCO3 (calcium carbonate) can be added to lakes to raise their pH levels and neutralize excess acid
102
why cant Venus support life
its atmosphere has thick white and yellow clouds of sulphuric acid, body can only work well in pH range around 7, this is why venus is inhabitable
103
what is there in a bee's sting? remedy for sting?
bees inject acidic liquid to protect themselves
| remedy- mild base like baking soda
104
what is there in a wasp's sting? remedy for sting?
wasp inject alkaline liquid, remedy - mild acid like vinegar
105
what is there in a ant's sting? remedy for sting?
ants inject methanoic acid, remedy - mild base like baking soda
106
what is there in a nettle leave's sting? remedy for sting?
nettle leaves have stinging hair that inject methanoic acid into skin of animal that touches them
TRADITIONAL REMEDY - using leaves of dock plant (which grow near nettle plant). dock plant leaves have basic chemicals that neutralize the acid
other remedy - mild base like baking soda
