STUDENT NAME:
Chemistry
CLASS 12/
2021 – 2022
Trimester 2
Chemistry
HAMZA BIN ABDULMUTILIB SCHOOL
Unit final revision term 2
Grade 12 G
Mr.
PREPARED BY
MOHAMED ABDELSAL
UNIT 1 CHEMICAL EQUILIBRIUM
1- Complete the table
Reactants
products
What are they?
Concentration in
the begining
After some time
By the end
2- What is chemical equilibrium?
3- Explain the chemical equilibrium in a-b?
4- What is the difference between homogeneous and
heterogeneous equilibrium?
5- Write equilibrium constant expressions for these equilibria.
N2 (g) + 3H2 (g) ⇌ 2NH3 (g)
N2O4 (g) ⇌ 2NO2 (g)
2H2S (g) ⇌ 2H2 (g) + S2 (g)
4NH3 (g) + 5O2 (g) ⇌ 4NO (g) + 6H2O (g)
6- Write equilibrium constant expressions for these
heterogeneous equilibrium.
2NaHCO3 (s) ⇌ Na2CO3 (s) + CO2 (g) + H2O (g)
C10H8 (g) ⇌ C10H8 (s)
CaCO3 (s) ⇌ CaO(s) + CO2 (g)
7- Mention Equilibrium characteristics?
123-
8- Calculate Keq for the equilibrium in N2O4 (g) ⇌ 2NO2 (g)
Using the data [N2O4] = 0.0185 mole/L and [NO2] = 0.0627
mole/L.
9-Calculate Keq for the equilibrium in CO (g) + 3H2 (g) ⇌ CH4 (g) +
H2O (g)
Using the data [CO] = 0.0613 mole/L, [H2] = 0.1839 mole/L, [CH4]
= 0.0387 mole/L, and [H2O] = 0.0387 mole/L.
10- Calculate the value of Keq for the equilibrium
constant expression Keq = given concentration
data
at one equilibrium position: [NH3] = 0.933 mole/L, [N2] = 0.533
mole/L, [H2] = 1.600 mole/L.
11-
CO (g) + 3 H2 (g) ⥂ CH4 (g) + H2O (g)
What is the effect of adding more CO in the previous reaction?
What is the effect of removing H2 in the previous reaction?
What is the effect of adding more CH4 in the previous reaction?
What is the effect of removing H2O in the previous reaction?
12 -
What is the effect of increasing pressure in the previous
reaction?
What is the effect of decreasing pressure in the previous
reaction?
What is the effect of increasing volume in the previous reaction?
What is the effect of decreasing volume in the previous
reaction?
13-
H2 +I2 ⇌ 2HI
What is the effect of decreasing volume or pressure in the
previous reaction?
14-
CO (g) + 3 H2 (g) ⇌ CH4 (g) + H2O (g ΔH° = -206.5 kJ
What is the effect of decreasing temperature in the previous
reaction?
What is the effect of increasing temperature in the previous
reaction?
15-
N2O4 (g) ⇌ 2NO2 (g)
ΔH° = 55.3 kJ
What is the effect of decreasing temperature in the previous
reaction?
What is the effect of increasing temperature in the previous
reaction?
16- How can we increase the rate of reaction without affecting
the equilibrium?
17- In the reactions 1,2,3,4 what is the effect of temperature on
the value of Keq?
1
2
3
4
Chemistry
Acids, Bases Revision
Choose the correct answer:
1) Which of the following formulas represents an acid containing one ionized hydrogen atom?
H3PO4
CH3COOH
H2SO4
2) All the following materials are amphoteric except:
OH−
H2O
H3O
KOH
HPO42−
3) in the reaction Ag+(aq) + 2NH3(aq) → [Ag(NH3)2]+(aq), Ag+ is considered to be
Lewis acid
Bronsted - Lowry acid
Lewis base
Bronsted-Lowry base
4) The formula of acid used as a flavouring for soft drinks is:
HNO3
H3PO4
H2SO3
H2SO4
5) Which of the following represents Lewis base?
H+
BF3
F−
Cu2+
6) In the reaction H+(aq) + NH3(aq)  NH4+(aq) ammonia represents a ____________base:
Bronsted-Lori
Lewis
Arrhenius
Bronsted - Laurie
7) The default formula M(OH) where M is an atom of a metal, can represent:
Hydrogenic acid
oxygenic acid
Hydroxide
basic oxide
8) In the reaction, HF + H2O  H3O+ + F−, the conjugate (acid - base) is:
H3O / F−
H3O+ / HF
HF / F−
H2O / HF
9) Which of the following is amphoteric?
H2SO4
H2SO3
SO32−
HSO3−
10) Which of the following pairs is considered a conjugate pair according to the Brønsted-Lowry
theory:
NH4+/NH3
Na2O / NaOH
H3O+/ NH3
11) which of the following formulas is chlorose acid?
HClO4
HClO3
HClO2
HCl /H3O+
HClO
12) Which substances in the equation CH3COOH(aq) + H2O(l)  CH3COO−(aq) + H3O+(aq) are Bronsted
- Lowry acids?
H3O+ , CH3COO−
CH3COO−
H2O
( 1 )
CH3COOH
Chemistry
Acids, Bases Revision
13) A group of friends went on a trip, one of them was exposed to wasp sting (basic medium), his
colleague thought to reduce his pain by wiping his skin with one of the following materials, which
one is suitable?
Table salt solution
lemon
soap
milk of magnesia
14) In the following equation CH3COOH + CO32−  CH3COO− + HCO3- , any of the following pairs
is a conjugate pair:
CO32− , CH3COOH
CH3COOH, CH3COO−
CH3COOH , HCO3−
CH3COO−, HCO3-
15) Which of the components of an aqueous solution of acetic acid has the highest concentration?
CH3COOCH3COOH
H3O+
H+
16) What element does react with HCl acid to produce H2 gas?
Copper
silver
zinc
gold
17) Which of the following is classified as a monoprotic acid?
H2CO3
H2SO4
HCOOH
H2S
18) Which acid that aqueous solution contains its particles and ions together?
HCl
HI
HBr
HF
19) The conjugate base for OH- is:
O2
O-2
H2O
H3O+
20) Which of the following substances is an example of Lewis’s Base:
NH3
ACl3
BF3
Ag+
21) What is the conjugate base of HPO4-?
H3PO4
H2PO4-
PO4-3
H2O
22) Which of the following does not dissolve in water to produce acidic solutions?
NO2
O2
SO2
NO
23) What is a diprotic acid from the following?
Acetic
phosphoric
hydrochloric
carbonic
24) Which of the following is not an oxyacid?
Hydrocyanic
hypochlorous
nitric
perbromic
25) The acid used for dyeing, engraving and hardening of steel has the formula:
H2SO3
H2SO4
HCN
( 2 )
H3PO4
Chemistry
Acids, Bases Revision
26) Using the following equation HF + NH3  NH4+ + FHF is Arrhenius acid
NH3 Bronsted-Laury acid
HF Arrhenius base
NH3 Lewis base
27) In the following equation: CH3COOH + CO3-2  CH3COO- + HCO3-, which of the following
is a conjugate pair:
(CH3COOH /HCO3-)
(CO3-2 / CH3COOH)
(CO3-2 / HCO3-)
(CO3-2/CH3COO-)
28) Many organic compounds that contain nitrogen such as aniline C6H5NH2 are:
Strong bases
weak bases
strong acids
weak acids
29) Ni2+(aq) + nH2O→ [Ni(H2O)n]2+(aq) , H2O in the reaction is:
Bronsted-Lowry acid
Bronsted Lowry base
Lewis acid
Lewis base
30) The amphoteric substance of the following is:
PO4-3
HPO4-2
H3O+
H3PO4
31) Which of the following is Tri-protic acid?
H2SO4
CH3COOH
H2CO3
H3PO4
32) Which of the following solutions contains the largest concentration of H3O+ hydronium ions?
0.1M NaCl
0.1M CH3COOH
0.1M HF
0.1MHI
33) What is the form of the acid that ants use for a chemical defence and to warn the rest of the
colony?
HCOOH
HCl
H3PO4
H2SO4
34) What substance can have the conjugate acid H2O and the conjugate base O2-?
OHO2
NO3H3O+
35) The ionization equation of an acidic indicator is HIn + H2O  H3O+ + In− , the presence of the
indicator in an acidic medium leads to:
(In–) Ion colour appears
pH decreases
(HIn) colour appears
the speed of forward reaction increases
36) When equivalent amounts of HCl acid and NaOH base are added, all the acidic and basic
characteristics disappear, except for:
Change Detector Colour
Interaction with zinc
Electrical Conductivity
Acidic taste
37) Aqueous solution of barium hydroxide Ba(OH)2 with a pH of 10, the base concentration is:
5 × 10−11
1×10−10
5×10−5
1×10−4
( 3 )
Chemistry
Acids, Bases Revision
38) Which of the following equal concentration solutions has the lowest pH value?
CH3COOH
HF
H2SO4
HCl
39) In acidic solutions, the indicator which is essentially a weak acid (HIn) is in the form
HIn
InOH
In−
In+
40) Pigments with colours affected by pH value are used as:
Standard primary materials
Indicators
Standard solutions
Lewis acids
41) If [H3O+] is greater than [OH-], the solution is:
Basic
acidic
neutral
amphoteric
42) The indicators are classified into three types according to:
Its colour
pH at which its colour changed
its molar mass
its polarity
43) The acid-base titration determines the volumes of two solutions have:
similar pH
same mass
same number of moles
Same molarity
44) The pH of 1x10-1M (HNO3) solution is:
1
1.3
2
5
45) At the equivalent point of a strong acid and weak base titration, the expected PH value is:
9
7
5
1
46) What is the concentration of the hydronium ion in a pOH 12.4 solution?
2.5 x10-2
8.9 x10-2
4.4x10-2
1x10-1
47) A security employee at an airport found two unknown substances (A and B) he took them to
the forensic laboratory, where substance (A) was titrated by substance (B) using methyl red
indicator, when adding zinc to substance (A), a gas rises that ignited with an explosion. What is
the identity of the two substances?
H2SO4 (A) /Ca(OH)2 (B)
NaOH (A) / HCl (B)
NH3 (A) / CH3COOH (B)
NH3 (A) / H2O (B)
48) Which of the following values express an acidic solution?
[OH-]= 10-5
PH =10
[H3O+]=10-10
POH=10
49) Which of the following is not a characteristic of the indicators?
Weak acids
change colours by changing the solution PH
strong acids
weak electrolytes
( 4 )
Chemistry
Acids, Bases Revision
50) Hydronium ion H3O+ concentration in pure water at 50°C (Kw = 5.3x10-14) is:
5.3x10-7 M H3O+
5.3x10-14 M H3O+
2.3x10-7 M H3O+
1x10-7MH3O+
51) The phenolphthalein indicator is used when titrating:
Strong acid and weak base
Weak acid and strong base
Weak acid and weak base
None of the above
52) The aqueous solution is neutral if:
Does not contain H3O+
[H3O+] = [OH-]
Does not contain ionized water molecules
Does not contain H3O+ or OH-
53) pH of 10-5M KOH is:
11
9
3
[OH−] = 1×10−12 M
[H3O+] = 1×10−3 M
5
54) The largest PH value is:
[H3O+] = 1×10−6 M
[OH−] = 1×10−10 M
55) One of the following solutions turns litmus papers to red:
POH=3
[OH−] = 1×10−7 M
POH=12
[OH-] = 1×10−5 M
56) What volume of 0.1M Oxalic acid H2C2O4 is needed to neutralize with 25ml of 0.145M KOH
solution?
18.125ml
37.2ml
67.1ml
33.6ml
57) The best way to measure the PH value of any solution:
Phenolphthalein detector
litmus paper
PH paper
PH meter
58) A 0.01M NaOH solution, has PH =?
10
7
12
2
59) The PH value of a solution is 6.32, so the POH value is:
6.32
7.68
4.8x10-7
2.1x10-8
60) What is the expected pH of industrial detergents?
10
7
4
2
61) What is the main criteria for classification of indicators?
Their primary materials
their molar mass
their transitional range
their resulting colour s
62) The solution is alkaline when:
[H3O+] >[OH-]
[H3O+] < [OH-]
( 5 )
[H3O+] =[OH-]
1x10-14 > [OH-]
Chemistry
Acids, Bases Revision
63) What is the expected pH value of soft drinks?
6
7
9
13
64) What is the name given to the PH range at which the detector changes its colour?
Equivalent point
Transition range
End point
Colour range
65) What is the factor that affects the ionic yield of water (Kw)?
Pressure
OH- concentration
H+ concentration
Temperature
66) which solution whose POH is 12?
[H3O+] = 1×10−2 M
[OH−] = 1×10−2 M
[H3O+] = 1×10−12 M
[OH−] = 12 M
67) Which of the following salt solutions does cation hydration occurs?
NaF
CH3COONa
NH4Cl
KNO3
68) What happens when a little amount of HCl acid is added to a solution consisting of NH4OH,
NH4Cl?
PH remains nearly constant
NH4+ concentration decreases
pH increases
Cl concentration decreases
69) What is the pH at the equivalence point of this titration?
10
9
5
1
70) Which indicator would be effective for detecting the end point of this titration?
methyl orange, with a range of 3.2-4.4
phenolphthalein, with a range of 8.2-10
bromocresol green, with a range of 3.8-5.4
thymol blue, with a range of 8.0-9.6
71) Hydrogen bromide (HBr) is a strong, highly corrosive acid. What is the pOH of a 0.0375M HBr
solution?
12.574
12.270
1.733
1.433
72) Cellular respiration produces about 38 mol of ATP for every mole of glucose consumed:
C6H12O6 + 6O2 → 6CO2 + 6H2O + 38ATP
If each mole of ATP can release 30.5 kJ of energy, how much energy can be obtained from a candy
bar containing 130.0 g of glucose?
27.4 kJ
836 kJ
1159 kJ
( 6 )
3970 kJ
Chemistry
Acids, Bases Revision
Use the table below to answer Questions 73–75.
73) Which acid is the strongest?
formic acid
lutidinic acid
cyanoacetic acid
barbituric acid
74) What is the acid dissociation constant of propanoic acid?
1.4 × 10-5
3.72 × 10-3
2.43 × 100
7.3 × 104
75) What is the pH of a 0.40M solution of cyanoacetic acid?
2.06
2.45
1.22
1.42
76) What does a value of K eq greater than 1 mean?
More reactants than products exist at equilibrium.
More products than reactants exist at equilibrium.
The rate of the forward reaction is high at equilibrium.
The rate of the reverse reaction is high at equilibrium.
77) Magnesium sulfate (MgSO4) is often added to water insoluble liquid products of chemical
reactions to remove unwanted water. MgSO4 readily absorbs water to form two different
hydrates. One of them is found to contain 13.0% H2O and 87.0% MgSO4 . What is the name of this
hydrate?
magnesium sulfate monohydrate
magnesium sulfate hexahydrate
magnesium sulfate dihydrate
magnesium sulfate heptahydrate
78) Water has an unusually high boiling point compared to other compounds of similar molar mass
because of
hydrogen bonding.
adhesive forces.
covalent bonding.
dispersion forces.
79) Which of these is a product of the first step in the ionization of phosphoric acid, H3PO4?
H3PO4
H2PO4
HPO4
PO4
80) Which one of the following could not be a Brownsted-Lowry acid?
H2O
H3O+
NH4+
BF3
81) Which of the following is a weak acid?
HCl
HNO3
HF
( 7 )
HClO4
Chemistry
Acids, Bases Revision
82) Which of the following is the strongest base according to the Bronsted-Lowry theory?
ClNO3FI-
Use the graph below to answer Questions 83 and 84.
83) Which compound has a solubility of 38 g/100 g H2O at 50 °C?
CaCl2
KClO3
KCl
NaCl
84) Which has the greatest increase in solubility as temperature increases?
Ce2(SO4)3
NaCl
CaCl2
Ce2(SO4)3
85) The acid ionization constant, Ka, is __________ for __________ acids.
largest, anhydride
largest, weak
smallest, strong
smallest, weak
86) If a 20-watt light bulb circuit passes through the following 0.10 M acid solutions, which 20-watt
bulb will be brightest?
hydrofluoric
carbonic
perchloric
hydrosulfuric
87) 7.Acetic acid is a weak acid. Which of the following gives the correct acid ionization constant
expression CH3COOH yields H+ + CH3COOKa = [H+]/[CH3COOH]
Ka = [CH3COOH]/[CH3COO-]
Ka = [CH3COO-]/[CH3COOH]
Ka = [CH3COO-][H+]/[CH3COOH]
( 8 )
Chemistry
Acids, Bases Revision
88) A solution of pH = 2.1 would be described as __________.
distinctly basic s
lightly basic
slightly acidic
distinctly acidic
89) Calculate the pH of 0.075M KOH.
10.4
11.12
12.88
11.46
90) About how much larger is [H+] for soft drinks than for coffee?
pH
100
10
1.7
soft drinks
3
0.6
coffee
5
91) Calculate Ka for a 0.05 M solution of the weak acid HF. The pH of the solution is 2.274.
6.3 x 10-4
5.7 x 10-4
0.12
0.11
92) Neutralization is the chemical process in which ____________.
sodium ions react with chloride ions to form sodium chloride
hydrogen ions react with chloride ions to form hydrogen chloride
sodium ions react with hydroxide ions to form sodium hydroxide
hydrogen ions react with hydroxide ions to form water
93) Which of the following cannot be a buffer?
a mixture of a weak acid and a weak base
a mixture of a strong acid and a weak base
a mixture of a weak acid and a strong base
a mixture of a strong acid and a strong base
94) Calculate the H+ ion and OH- ion concentrations in a 0.50M solution of HBr. Assume HBr is a
strong acid.
[H+]
= 0.50M and [OH-] = 0.50M
[H+] = 0.50M and [OH-] = 2.0 x 10-14M
[H+] = 0.50M and [OH-] = 2.0M
[H+] = 1.0 x 10-7M and [OH-] = 1.0 x 10-7M
95) Which of these salts will produce an acidic solution?
KF
NH4Cl
NaNO3
NaCl
96) Which of the following is a strong base?
NH3
HCO3-
HCOOH
NaOH
97) Under what condition is the OH- ion concentration in water expected to be zero?
in a solution of strong acid
in a solution of strong base
in a solution of weak base
never
98) A base that dissociated entirely into metal ions and hydroxide ions is known as a ________.
NaOH(s) yields Na+(aq) + OH-(aq)
strong base
weak base
( 9 )
concentrated base
dilute base
Chemistry
Acids, Bases Revision
99) Ammonia is a weak base. Which of the following gives the correct base ionization constant
expression? NH3(aq) + H2O(l) yields NH4+(aq) + OH-(aq)
Kb = [NH4+]/[NH3]
Kb = [NH4+][OH-]/[NH3]
Kb = [OH-]/[NH3]
100) Calculate the pH of a solution that has a [OH-] = 2.50 x 10-4M.
0.4
3.6
-3.6
Kb = [NH3]/[NH4+]
10.4
101) Calculate the Ka for a 0.10 M solution of the weak acid HCN; the pH of the solution is 5.104.
6.2 x 10-11
6.2 x 10-10
6.2
-6.2 x 10-11
[H+][OH-]
[H2O][OH-]
102) Kw is the product of ________.
[H2O][H+]
[H2O][H2O]
103) Which of these reactions has the net ionic equation shown below?
HCl(aq) + NaOH(aq) yields NaCl(aq) +H2O(l)
2Na(s) +2H2O(l) yields H2(g) +2NaOH(aq)
KCl(aq) +AgNO3(aq) yields AgCl(s) +KNO3(aq)
Ba(NO3)2 + Na2SO4 yields 2NaNO3(aq) +BaSO4(s)
104) What does a color change indicate in a titration?
The pH of the solution is 7.00
The solution is buffered.
The equivalent point has been reached.
The solution is neutral.
105) 17.5 mL of 0.1000 M NaOH was required to neutralize 25.0 mL of HCl. What was the molarity
of the HCl?
3.00 M HCl
14.3 M HCl
( 10 )
0.0700 M HCl
0.0300 M HCl