HND Practice Chemistry MCQ
Higher National Diploma in Biomedical Science
Chemistry for Biology
(BIOM 502/1)
Practice Multiple Choice Question
Prepared by:
Dr. Mathi Kandiah PhD
Update: November 2014
Page 1 of 32
HND Practice Chemistry MCQ
Chemistry for Biology
Practice Multiple Choice Question
Answer ALL the questions. You shall mark only one answer.
1) In your lab, Concentration and Temperature Effects on Equilibrium, you studied
the aqueous reaction:
—
Fe+3 + SCN
(Light Yellow)
FeSCN2+
(Deep Red)
Use your knowledge of equilibrium to answer questions 1 and 2.
Adding Fe(NO 3 ) 3 produced the following change in the equilibrium:
a) The color in the test tube became a deeper red color because the equilibrium
shifted to make more reactants.
b) The color in the test tube became a deeper red color because the equilibrium
shifted to make more products.
c) The color in the test tube became a lighter color because the equilibrium
shifted to make more reactants.
d) The color in the test tube became a lighter color because the equilibrium
shifted to make more products.
2) The reaction you studied is became a deeper red color when placed in an ice
bath. This means that the reaction is
a)
b)
c)
d)
Exothermic.
Endothermic.
There is not enough information given to answer the question.
None of the above are correct.
3) Which of the following quantities, used in the calculation of the lattice energy of lithium
oxide, Li 2 O has a negative value?
a)
b)
c)
d)
The enthalpy change of atomization of lithium.
The first ionization energy of lithium.
The first electron affinity of oxygen.
The second electron affinity of oxygen.
Page 2 of 32
HND Practice Chemistry MCQ
4) How many moles of ions are present in 20 cm3 of 0.050 mol dm-3 calcium chloride
solution, CaCl 2 (aq)?
a)
b)
c)
d)
0.0050
0.0030
0.0020
0.0010
5) Avogadro constant is 6.0 x 1023 mol-1. The number of atoms in 1 mol of dinitrogen
tetroxide, N 2 O 4 , is
a)
b)
c)
d)
3.6 x 1024
1.8 x 1024
6.0 x 1024
1.0 x 1023
6) Which of the following pairs of compounds could form a polyamide?
a) Cl
CH2
CH2
Cl
and
H2N
NH2
CH2
CH2
O
O
b) OH
CH2
CH2
OH and
C
C
CH2
CH2
NH2
H2N
O
O
C
c)
CH2
CH2
C
and
HO
OH
O
O
C
d)
Cl
CH2
CH2
C
and
CH3
H2N
CH2
CH2
NH2
CH2
NH2
Cl
Page 3 of 32
HND Practice Chemistry MCQ
7) Which of the following compounds shows geometric (E-Z or cis-trans) isomerism?
a)
b)
c)
d)
but-1-ene
2-methylbut-1-ene
but-2-ene
2-methylbut-2-ene
8) What is the systematic name for the compound with the following formula?
CH3CH
CHCH3
CH3 CH2CH3
a)
b)
c)
d)
2-methyl-3-ethylbutane
1,2,3-trimethylbutane
2,3-dimethylpropane
2,3-dimethylpentane
9) Which of the equations below represents the first electron affinity for oxygen?
a)
b)
c)
d)
O 2 (g) + 2e- → 2O—(g)
O 2 (g) - 2e- → 2O—(g)
½O 2 (g) + e- → O—(g)
O(g)
+ e- → O—(g)
10) Which equation represents the reaction for which the enthalpy change, ∆H, is the
mean bond energy of the C-F bond?
a)
b)
c)
d)
CF 4 (g) → C(g) + 4F(g)
¼CF 4 (g) → ¼C(g) + F(g)
C(g) + 4F(g) → CF 4
¼C(g) + F(g) →¼CF 4
Page 4 of 32
HND Practice Chemistry MCQ
11) Which pair of ions is isoelectronic?
a)
b)
c)
d)
Ca2+ and O2Na+ and O2Li+ and Cl-The
Mg+ and Cl-
12) The equation for the complete combustion of ethane is
2C 2 H 6 (g) + 7O 2 (g) → 4CO 2 (g) + 6H 2 O(l)
What volume of oxygen, measured at room temperature and pressure, is needed to
completely burn 0.1 mol of ethane?
[The volume of 1 mol of any gas measured at room temperature and pressure is 24
dm3]
a) 2.4 dm3
b) 4.8 dm3
c) 8.4 dm3
d) 16.8 dm3
13) The systematic name of the compound with skeletal formula shown below is
OH
a) 1,1-dimethylethanol
b) 2,2-dimethylethanol
c) 2-methylpropan-1-ol
d) 2-methylpropan-2-ol
Page 5 of 32
HND Practice Chemistry MCQ
14) In which series of compounds does the covalent character increase, going from left to
right?
a) NaCl, MgCl 2 , AlCl 3 , SiCl 4
b) SiO 2 , Al 2 O 3 , MgO, Na 2 O
c) Lil, NaI, KI, RbI
d) KI, KBr, KCl, KF
15) Going down Group 2 from Calcium to Barium
a) The first ionization energy of the element increases
b) The strength of the metallic bonding increases
c) The polarizing power of the 2+ ion decreases
d) The stability of the nitrate to heat decreases
16) In the industrial process involving gas phase reactions to produce ammonia, many
collisions between molecules are unsuccessful because,
a)
b)
c)
d)
Gas phase reactions are reversible
The collisions are not energetic enough to break the bonds in the molecule
Gas phase reactions can occur when a catalyst is present
Gas phase reactions can occur when UV lights is present
17) Hydrochloric acid and sodium carbonate solution react as shown below.
2HCl(aq) + Na 2 CO 3 (aq) → 2NaCl(aq) + CO 2 (g) +H 2 O(l)
Which sample of sodium carbonate solution will be neutralized by 20 cm3 of 0.05 mol
dm-3 hydrochloric acid?
a)
b)
c)
d)
10 cm3, 0.05 mol dm-3
40 cm3, 0.05 mol dm-3
40 cm3, 0.1 mol dm-3
10 cm3, 0.1 mol dm-3
Page 6 of 32
HND Practice Chemistry MCQ
18) The following data are provided.
ClO-(aq) + H 2 O(l) + eCl 2 (aq) + 2ea) + 1.36
2
b) +
1.36
2
½Cl 2 + 2OH- (aq)
2Cl-(aq)
Eθ / V
+0.40
+1.36
_ 0.40 V
+ 0.40 V
c) + 1.36 - 0.40 V
d) + 1.36 + 0.40 V
19) Which of the following is always proportional to Eθ cell for a chemical reaction?
a)
b)
c)
d)
∆H reaction
∆S system
∆Ss urrounding
∆S total
20) Transition metals are often used as heterogeneous catalysts. Which of the following
process does not occur in catalyzed reaction?
a)
b)
c)
d)
Adsorption of reactant molecules on the surface of the metal.
Bond breaking in the reactant molecules
Desorption of product molecules from the surface of the metal.
An overall change in the oxidation number of the metal.
21) The total number of isomers of dibromobenzene, C 6 H 4 Br 2 , containing a benzene ring
is
a)
b)
c)
d)
2
3
4
5
Page 7 of 32
HND Practice Chemistry MCQ
22) The electrode system based on the half-equation below has the standard electrode
potential +1.51 V.
‐
MnO 4 (aq) + 8H+(aq) + 5e-
Mn2+(aq) + 4H 2 O(l)
Eθ = +1.51 V
Which of the following statements about this electrode system is correct?
a)
b)
c)
d)
Changing the concentration of Mn2+(aq) would cause a change in the electrode
Mn2+(aq) is acting as an oxidizing agent
The electrode used is made of manganese
When connected to a standard hydrogen electrode, the resulting cell voltage would
be +0.51V
23) The electronic configuration of Aluminium is
a)
b)
c)
d)
2,3
2,2,3
2,2,8
2,8,3
24) Iron reacts with hydrochloric acid to form iron(II) chloride and hydrogen gas. 2g of iron
is added to 100cm3 of dilute hydrochloric acid. Which conditions produces the slowest
reaction?
a)
b)
c)
d)
iron pieces at 50°C
iron powder at 50°C
iron pieces at 25°C
iron powder at 25°C
25) Platinum catalyses the reaction between sulphur dioxide SO 2 and oxygen O 2 to form
sulphur trioxide SO 3 . Which of the statements 1, 2 or 3 is/are correct?
1. more sulphur trioxide is formed when more catalyst is used
2. the catalyst increases the rate of reaction between sulphur dioxide and oxygen
3. when the reaction is complete the platinum catalyst has not lost any mass
Page 8 of 32
HND Practice Chemistry MCQ
a)
b)
c)
d)
1 and 2
2 and 3
1, 2 and 3
1 and 3
26) Limestone chips were reacted with acid in a beaker placed on a one pan electric
balance. The mass of the reacting mixture was measured at regular time
intervals. Which graph would you expect the results to be like?
a)
b)
c)
d)
Graph W
Graph Z
Graph Q
Graph Y
27) In a rates experiment the following carbon dioxide gas volumes were recorded by a
student resulting from an acid-limestone reaction.
time
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
(min)
Vol
0
(cm3)
8
15 21 26 30 33 36 38 39 40 40 40
At what approximate time is the speed of the reaction 8cm3 gas/min?
a)
b)
c)
d)
1.0 to 1.5 min
1.0 to 1.5 min
2.0 to 2.5 min
5.0 to 5.5 min
Page 9 of 32
HND Practice Chemistry MCQ
28) When hydrogen chloride is heated it breaks down into hydrogen and fluorine.
The equation can be written as:
2HCl(g) ==> H 2 (g) + Cl 2 (g)
Use the bond energies shown below to calculate the energy change that takes place
when 2 moles of hydrogen chloride thermally decomposes in this way.
(bond energies in kJ/mol: H-H = 440; Cl-Cl = 245; H-Cl = 430)
a)
b)
c)
d)
175 kJ taken in
175 kJ given out
685 kJ taken in
860 kJ given out
29) When an endothermic reaction takes place, the reaction mixture takes in heat
because?
a) endothermic changes always produce energy
b) in an endothermic change the products are more stable than the reactants
c) more energy is absorbed when existing bonds are broken than is given out when
new bonds are formed in the products
d) energy is always absorbed in a chemical change which makes new substances
30) In which reaction is a metal oxide reduced?
a)
b)
c)
d)
water (steam) + magnesium ==> magnesium oxide + hydrogen
carbon + water ==> hydrogen + carbon monoxide
copper oxide + carbon ==> copper + carbon dioxide
magnesium + water ==> magnesium hydroxide + hydrogen
31) Which electronic diagram is correct for the compound formed by combining a metal M,
from Group 3, with a non-metal X from Group 7 of the Periodic Table?
Page 10 of 32
HND Practice Chemistry MCQ
a)
b)
c)
d)
32) Solid iodine consists of I 2 molecules symmetrically arranged in a crystal
lattice. Relatively high temperatures are needed to change iodine molecules into iodine
atoms because the?
a)
b)
c)
d)
33)
iodine is an element and a non-metal
forces holding the molecules together in iodine are weak
forces holding the atoms together in an iodine molecule are strong
iodine is ionically bonded and the forces between ions are very strong
CuSO4.5H2O(
s)
CuSO4(
s)
+ 5H2O(
g)
The equation shows the effect of heat on the salt hydrated copper(II) sulphate. Which
statement is TRUE about this reversible reaction?
a)
b)
c)
d)
purified and let out into the atmosphere without causing pollution
recycled through the reaction chamber immediately
collected and stored for later ammonia production
burned to preheat the gases coming into the hot reactor to stop it cooling down
Page 11 of 32
HND Practice Chemistry MCQ
34) On the reaction profile diagrams above, which energy change corresponds to the
overall energy change for the uncatalysed exothermic formation of ammonia?
a)
b)
c)
d)
profile 2, E6
profile 2, E4
profile 1, E2
profile 1, E3
35) In a galvanic cell, what is the pathway of electron flow
a)
b)
c)
d)
Direction: anode to cathode, Medium: salt bridge
Direction: anode to cathode, Medium: external wire
Direction: cathode to anode, Medium: salt bridge
Direction: cathode to anode, Medium: external wire
36) What is the total number of sigma bonds found in the following compound?
H3C
a)
b)
c)
d)
C
H
C
CH
C
C
CH
8
10
11
15
Page 12 of 32
HND Practice Chemistry MCQ
37) Which of the following alkanes would have the highest boiling point?
a) H C
3
b)
CH3
c)
H3C
d)
CH3
H2
C
H2
C
H2
C
CH3
CH3
C
CH
CH3
CH3
H2
C
H2
C
H
C
H2
C
CH3
H2
C
H2
C
H2
C
H
C
CH3
CH3
CH3
H
C
CH3
CH3
38) What is the IUPAC name for the following compound?
CH3
CH3
C
H2
C
CH3
H
C
CH3
CH3
a) 1,3-pentamethylpropane
b) 1,1,3,3-tetramethylbutane
c) 2,4,4-trimethylpentane
d) 2,2,4-trimethylpentane
39) Which of the Fischer projections correctly depicts the following compound?
OH
H
C
H
OH
C
C
H3C
HO
CH3
H
Page 13 of 32
HND Practice Chemistry MCQ
CH3
a)
H
HO
C
HO
C
H
H
C
OH
CH3
CH3
b)
H
HO
C
H
C
HO
C
OH
H
CH3
CH3
c)
H
C
H
C
HO
C
OH
OH
H
CH3
CH3
d)
HO
C
H
HO
C
H
HO
C
H
CH3
40) Which process represents the C-Cl bond enthalpy in tetrachloromethane?
a)
b)
c)
d)
CCl 4 (g) → C(g) + 4Cl(g)
CCl 4 (g) → CCl 3 (g) + Cl(g)
CCl 4 (l) → C(g) + 4Cl(g)
CCl 4 (g) → C(s) + 2Cl 2 (g)
Page 14 of 32
HND Practice Chemistry MCQ
41) When equal volumes of four 0.1 mol dm-3 solutions are arranged in order of
increasing pH (lowest pH first), what is the correct order?
a) CH 3 COOH < HNO 3 < CH 3 CH 2 NH 2 < KOH
b) HNO 3 < CH 3 COOH < CH 3 CH 2 NH 2 < KOH
c) CH 3 CH 2 NH 2 < HNO 3 < CH 3 COOH < KOH
d) KOH < CH 3 CH 2 NH 2 < CH 3 COOH < HNO 3
42) Which is the correct combination
a)
b)
c)
d)
Intermolecular forces
weak
weak
strong
strong
Boiling point
low
low
high
low
H vap
low
high
low
low
43) Two moles of electrons are passed through an electrolytic cell containing molten
sodium chloride. The same charge is passed through a second cell containing aqueous
sodium chloride. In both cells the electrodes are made of platinum. Which statement is
correct?
a)
b)
c)
d)
One mole of sodium metal will be formed in the first cell
Chlorine gas will be formed at the cathodes of both cells
One mole of hydrogen gas will be formed in the second cell
One mole of oxygen gas will be formed at the anode of the second cell
44) Consider these standard electrode potentials.
Mg2+(aq) + 2eZn2+(aq) + 2e-
Mg(s)
Zn(s)
Eθ = - 2.36 V
Eθ = - 0.76 V
What is the cell potential for the voltaic cell produced when the two half-cells are
connected?
a) - 1.60 V
b) + 1.60 V
c) – 3.12 V
d) + 3.12 V
Page 15 of 32
HND Practice Chemistry MCQ
45) What is the IUPA name for HCOOCH 2 CH 2 CH 3 ?
a)
b)
c)
d)
Butanoic acid
Butanol
Methy propanate
Propyl methanoate
46) Which statement best describes the intramolecular bonding in HCN(l)?
a)
b)
c)
d)
Electrostatic attractions between H+ and CN- ions
Only van der Waals’ forces
Van der Waals’ forces and hydrogen bonding
Electrostatic attractions between pair of electrons and positively charged nuclei
47) Which of the following best describes the formation of πbonds?
a)
b)
c)
d)
They are formed by the sideways overlap of parallel orbitals
They are formed by the axial overlap of orbitals
They are formed by the sideways overlap of an s and p orbital
They are formed by the axial overlap of either s or p orbitals.
48) What is the standard entropy change, ∆Sθ, for the following reaction?
2CO(g) + O 2 (g) → 2CO 2 (g)
Sθ /JK-1 mol -1
a)
b)
c)
d)
CO(g)
198
O 2 (g)
205
CO 2 (g)
214
-189
-173
+173
+189
Page 16 of 32
HND Practice Chemistry MCQ
49) For the reaction below:
H 2 (g) + I 2 (g)
2HI(g)
At a certain temperature the equilibrium concentrations, in mold m-3, are
[H 2 (g)] = 0.30, [I 2 (g)] = 0.30, [HI(g)] = 3.0
What is the value of K c ?
a) 1.0 x 10-2
b) 10
c) 33
d) 1.0 x 102
50) Consider the following reaction.
5Br—(aq) + BrO 3 — (aq) + 6H+(aq) → 3Br 2 (aq) + 3H 2 O(l)
The rate expression for the reaction is found to be:
Rate =κ[Br—][BrO 3 —][H+]2
Which statement is correct?
a) The overall order is 12
b) Doubling the concentration of all of the reactants at the same time would increase
the rate of the reaction by a factor of 16.
c) The units of the rate constant, κ, are mold m-3s-1.
d) A change in concentration of Br or BrO 3 does not affect the rate of the reaction.
51) Consider the following reaction mechanism.
Step 1
Step 1
H 2 O 2 + I— → H 2 O + IO—
H 2 O 2 + IO— → H 2 O + O 2 + I—
slow
fast
Which statement correctly identifies the rate-determining step and the explanation?
Page 17 of 32
HND Practice Chemistry MCQ
a)
b)
c)
d)
Step 2 because it is the faster step
Step 1 because it is the slower step
Step 1 because it is the first step
Step 2 because it is the last step
N 2 O 4 (g)
52)
2NO 2 (g)
K c = 5.0 x 10—3
In an equilibrium mixer of these two gases, [N 2 O 4 ] = 5.0 x 10—1 mol dm—3. What is the
equilibrium concentration of NO 2 in mol dm—3?
a)
b)
c)
d)
5.0 x 10—1
—
5.0 x 10 2
5.0 x 10—3
2.5 x 10—4
53) Which statement(s) is(are) correct about the effect of adding a catalyst to a system at
equilibrium?
I.
II.
III.
a)
b)
c)
d)
The rate of the forward reaction increases.
The rate of the reverse reaction increases
The yield of the products increases
I only
III only
I and II only
I, II and III
54) 100 cm3 of a NaOH solution of pH 12 is mixed with 900 cm3 of water. What is the pH
of the resulting solution?
a)
b)
c)
d)
1
3
11
13
Page 18 of 32
HND Practice Chemistry MCQ
55) Which method will distinguish between equimolar solutions of a strong base and a
strong acid?
I.
II.
III.
a)
b)
c)
d)
Add magnesium to each solution and look for the formation of gas bubbles
Add aqueous sodium hydroxide to each solution and measure the
temperature change.
Use each solution in a circuit with a battery and lamp and see how bright the
lamp glows.
I and II only
I and III only
II and III only
I, II and III
56) Which statement about indicators is always correct?
a)
b)
c)
d)
The mid-point of the pH range of an indicator is 7
The pH range is greater for indicators with higher pK a values
The colour red indicates an acidic solution
The pK a value of the indicator is within its pH range
57)
Which energy value(s) will change when a catalyst is added?
a)
b)
c)
d)
I only
II only
II and III only
I, II and III
Page 19 of 32
HND Practice Chemistry MCQ
58) Consider the following reversible reaction
Cr 2 O 7 2—(aq) + H 2 O(l)
2CrO 4 2—(aq) + 2H+ (aq)
What will happen to the position of equilibrium and the valus of K c when more H+ ions
are added at constant temperature?
a)
b)
c)
d)
Position of equilibrium
Shifts to the left
Shifts to the right
Shifts to the right
Shifts to the left
Value of K c
decreases
increases
does not change
does not change
59) Which reaction has the greatest increase in entropy?
a)
b)
c)
d)
C 3 H 8 (g) + 5O 2 (g) → 3CO 2 (g) + 4H 2 O (g)
H 2 (g) + Cl 2 (g) → 2HC l (g)
N 2 (g) + 3H 2 (g) → 2NH 3 (g)
C 2 H 4 (g) + H 2 (g) → C 2 H 6 (g)
60) Consider this equilibrium reaction in a sealed container:
H 2 O (g)
H 2 O (l)
What will be the effect on the equilibrium increasing the temperature from 20 ºC to 30
ºC?
a)
b)
c)
d)
More of the water will be in the gaseous state at equilibrium
More of the water will be in the liquid state at equilibrium
At equilibrium the rate of condensation will be greater that the rate of evaporation
At equilibrium the rate of evaporation will be greater that the rate of condensation
61) Which compound can exist as stereoisomers?
a)
b)
c)
d)
CH 3 CH 2 CHO
CH 3 CH 2 COCH 3
CH 3 CH(CH 3 ) 2
CH 3 CH 2 CHOHCH 3
Page 20 of 32
HND Practice Chemistry MCQ
62) What is the order of increasing energy of the orbital within a single energy level?
a)
b)
c)
d)
d<s<f<p
s<p<d<f
p<s<f<d
f<d<p<s
63) The indicator, HIn is used in a titration between an acid and base. Which statement
about the dissociation of the indicator, HIn is correct?
HIn (aq)
Colour A
a)
b)
c)
d)
H+ (aq) + In— (aq)
Colour B
In a strongly alkaline solution, colour B would be observed
In a strongly acidic solution, colour B would be observed
[In—] is greater than [HIin] at the equivalence point
In a weakly acidic solution colour B would be observed
64) Which would be the best method to decrease the random uncertainty of a
measurement in an acid-base titration?
a)
b)
c)
d)
Repeat the titration
Ensure your eye is at the same height as the meniscus when reading the burette
Use a different burette
Use a different indicator for the titration
65) The geometry and bond angle of the sulfide ion (SO 3 2—) are best described as
a)
b)
c)
d)
Pyramidal, 107º
Tetrahedral, 109º
Bent, 104º
Trigonal planar, 120º
Page 21 of 32
HND Practice Chemistry MCQ
66) What type of solid materials are typically hard, have high melting points and poor
electrical conductivities?
I.
II.
III.
Ionic
Metallic
Covalent-network
a) I and II only
b) I and III only
c) II and III only
d) 1, II and III
67) Consider the following reaction:
—
H 2 SO 3 (aq) + Sn4+ (aq) + H 2 O (l) → Sn 2+ (aq) + HSO 4 (aq) + 3H+ (aq)
Which statement is correct?
a)
b)
c)
d)
H 2 SO 3 is the reducing agent because it undergoes reduction
H 2 SO 3 is the reducing agent because it undergoes oxidation
Sn4+ is the oxidizing agent because it undergoes oxidation
Sn4+ is the reducing agent because it undergoes oxidation
68) Which pair of species is listed in increasing order of the property given?
a)
b)
c)
d)
Ionisation energy: O, F
Radius: Mg, Mg2+
Melting point: I 2 , Br 2
Covalent character: HI, HBr
69) Which species does not contain at least one 90º bond angle?
a)
b)
c)
d)
CF 4
PF 5
SF 6
SiF 6 2—
Page 22 of 32
HND Practice Chemistry MCQ
70) Which statement about the information below is correct?
C 2 H 4 (g) +H 2 (g) → C 2 H 5 (g)
∆Hθ = - 137kJ
a) The total energy of the bonds broken in the reactants is greater than the total
energy of the bonds formed in the product.
b) The bonds broken and the bonds made are of the same strength
c) The total energy of the bonds broken in the reactants is less than total energy of the
bonds formed in the product
d) No conclusion can be made about the sums of the bond enthalpies in the product
compared with the reactants
71) When the compounds below are listed in order of decreasing boiling point (highest to
lowest) what is the correct order?
1. Ethane
2. Fluroethane
3. Ethanol
4. Ethanoic acid
a) 4, 3, 1, 2
b) 4, 3, 2, 1
c) 3, 4, 1, 2
d) 2, 1, 3, 4
72) Equal masses of powdered calcium carbonate were added to separate solutions of
hydrochloric acid. The calcium carbonate was in excess. The volume of carbon dioxide
was measured at regular intervals. Which curves best represent the evolution of
carbon dioxide against for the acid solutions shown in the table below.
Page 23 of 32
HND Practice Chemistry MCQ
a) I - 25 cm3 of 2 mol dm-3 HCl, III - 25 cm3 of 2 mol dm-3 HCl, IV - 25 cm3 of 2 mol
dm-3 HCl
b) I - 25 cm3 of 2 mol dm-3 HCl, IV - 25 cm3 of 2 mol dm-3 HCl, III - 25 cm3 of 2 mol
dm-3 HCl
c) I - 25 cm3 of 2 mol dm-3 HCl, II - 25 cm3 of 2 mol dm-3 HCl, III - 25 cm3 of 2 mol
dm-3 HCl
d) II - 25 cm3 of 2 mol dm-3 HCl, I - 25 cm3 of 2 mol dm-3 HCl, III - 25 cm3 of 2 mol
dm-3 HCl
73) The combustion of methanol is described by the following equation:
CH 3 OH + O 2 → CO 2 + 2H 2 O
Use Hess's Law to calculate the enthalpy of combustion (ΔH C ) of methanol given the
following standard enthalpies of formation (ΔH f θ ).
ΔH f θ methanol = - 238.0 kJ mol-1
ΔH f θ H2O = - 285.5 kJ mol-1
ΔH f θ CO2 = - 393.51 kJ mol-1
ΔH f θ O2 = 0 kJ mol-1
a) -1203.2 kJ mol-1
b) - 441.35 kJ mol-1
c) + 727.2 kJ mol-1
d) - 727.2 kJ mol-1
74) Which of the following statements will always apply when a reversible chemical
reaction has attained equilibrium?
a)
b)
c)
d)
All reactants will convert to products
The reaction proceeds alternately in the forward and reverse directions
The Gibbs free energy of the system reaches a minimum
The forward reaction will dominate over the reverse reaction
Page 24 of 32
HND Practice Chemistry MCQ
75) A drug used to treat hypertension undergoes a decomposition reaction to give an
insoluble product. Calculate the temperature at which this reaction becomes
spontaneous if the enthalpy of the reaction at 298 K is 51 kJ mol-1 and the entropy of
the reaction at this temperature is 118.74 J K-1 mol-1.
a)
b)
c)
d)
430 K
2300 K
0.5 K
430 ºC
76) A section of the polypeptide made from a single amino acid is shown below.
H
H
O
H
H
O
N
C
C
N
C
C
CH3
CH3
The polypeptide was heated with excess dilute sodium hydroxide solution until no
further change took place.
Which of the following products is formed?
a)
H2N
H
H
C
C
H
H
O
C
O-
H
b)
H2N
C
CH3
O
C
O-
Page 25 of 32
HND Practice Chemistry MCQ
H
c)
H2N
O
C
C
CH3
OH
H
d)
H3N+
C
CH3
O
C
O-
77) The value of ∆H for the reaction below is -72 kJ. How many kJ of heat are released
when 1.0 mol of HBr is formed in this reaction?
H 2 (g) + Br 2 (g) → 2HBr(g)
a)
b)
c)
d)
144
– 72
36
72
78) Which of the following criteria is valid to represent a reversible reaction
a)
b)
c)
d)
∆S universe = ∆S system + ∆S surroundings = 0
∆S universe = ∆S system + ∆S surroundings > 0
Above all
None of the above
79) Which is a buffer solution?
I. 0.01 mol dm−3 HCl, 0.01 mol dm–3 NaCl
II. 0.01 mol dm−3 CH 3 COOH, 0.01 mol dm–3 CH 3 COONa
Page 26 of 32
HND Practice Chemistry MCQ
a)
b)
c)
d)
I only
II only
Both I and II only
Neither I or II
80) Which one of the following species can act as both a Brønsted-Lowry acid and
base in aqueous solution?
a)
b)
c)
d)
CH 3 COOH
NO 3 —
H 2 PO 4 —
OH—
81) What is the relationship between relationship between Ka and PKa?
a) pKa = −log Ka
b) pKa =
1.0 × 10 −14
Ka
c) pKa = log Ka
d) pKa =
1.0
Ka
82) The pH of the solution is 2. If its pH is increased to 6, how many times greater is
the [H+] of the original solution?
a)
b)
c)
d)
3
4
1000
10 000
83) Which curve is produced by the titration of a 0.1 mol dm−3 weak base with 0.1
mol dm−3 strong acid?
Page 27 of 32
HND Practice Chemistry MCQ
12
A.
12
B.
8
8
pH
pH
4
4
Volume of titrant
12
C.
Volume of titrant
12
D.
8
8
pH
pH
4
4
Volume of titrant
a)
b)
c)
d)
Volume of titrant
A
B
C
D
84) The K a value of an acid is 1.0 x 10—2. What is the K b value for its conjugate base.
a)
b)
c)
d)
1.0 × 10−2
1.0 × 10−6
1.0 × 10−10
1.0 × 10−12
85) Four aqueous solution, I, II, III and IV are listed below
I.
II.
III.
IV.
0.100 mol dm–3 HCl
0.010 mol dm–3 HCl
0.100 mol dm–3 NaOH
0.010 mol dm–3 NaOH
What is the correct order of increasing pH of these solutions?
a)
b)
c)
d)
I, II, III, IV
I, II, IV, III
II, I, III, IV
II, I, IV, III
Page 28 of 32
HND Practice Chemistry MCQ
86) Which is the conjugate acid-base pair in the following reaction
HNO 3 +H 2 SO 4
H 2 NO 3 + + HSO 4 —
a) HNO 3 and H 2 SO 4
b) HNO 3 and H 2 NO 3 +
c) HNO 3 and HSO 4 —
d) H 2 NO 3 + and HSO 4 —
87) Which solution mixture would produce a buffer solution when dissolved in 1.0
dm3 of water?
a)
b)
c)
d)
0.50 mol of CH 3 COOH and 0.50 mol of NaOH
0.50 mol of CH 3 COOH and 0.25 mol of NaOH
0.50 mol of CH 3 COOH and 1.00 mol of NaOH
0.50 mol of CH 3 COOH and 0.25 mol of Ba(OH) 2
88) Reaction rates are affected by concentration, collision geometry, and the
presence of a catalyst. Which one of the following statements is FALSE?
a)
b)
c)
d)
Larger concentrations of reacting particles increases the number of collisions.
Molecules that do not collide in the correct orientation lower the reaction rate.
The slowest step in the mechanism determines the rate.
A catalyst increases the speeds of the reacting particles.
89) Use the potential energy diagram to answer questions 89-91
What is the potential energy of the products?
Page 29 of 32
HND Practice Chemistry MCQ
a)
b)
c)
d)
200
250
350
450
90) What is the potential energy of the activated complex?
a)
b)
c)
d)
200
250
350
450
91) What is the heat of reaction?
a)
b)
c)
d)
100
150
200
450
92) Which statement is true?
a)
b)
c)
d)
The electrical conductivity of a metal increases with temperature
The electrical conductivity of a semiconductor increases with temperature
The resistivity of a semiconductor increases with temperature
Metals and semiconductors have similar electrical conducting properties
—
93) In solid NaCl, the coordination number of the Na+ and Cl ions are respectively,
a)
b)
c)
d)
6 and 6
8 and 8
12 and 12
6 and 8
Page 30 of 32
HND Practice Chemistry MCQ
94) Which one of the following is not a form of chemical bonding?
a)
b)
c)
d)
covalent bonding
hydrogen bonding
ionic bonding
metallic bonding
95) Which of the following statements is incorrect?
a) the greater the number of electrons in a molecule, the greater the van der Waals
forces
b) the layers in graphite are held together by van der Waals forces
c) the boiling point of noble gases increases down the group
d) water has a higher than expected boiling point because of intermolecular van der
Waals forces
96) The correct order of increasing attractive strength for weak intermolecular forces is,
a)
b)
c)
d)
dipole-dipole interaction, hydrogen bonding, van der Waals forces
van der Waals forces, dipole-dipole interaction, hydrogen bonding
hydrogen bonding, dipole-dipole interaction, van der Waals forces
dipole-dipole interaction, van der Waals forces, hydrogen bonding
97) A Lewis base is a
a)
b)
c)
d)
lone pair acceptor
lone pair donor
proton acceptor
proton donor
98) Which one of the following is not true about metallic bonding?
a)
b)
c)
d)
it gives rise to excellent electrical conductivity
electrons are free to move throughout the structure
the strength of metallic bonds increases down a group
the strength of metallic bonding affects the boiling point of metals
Page 31 of 32
HND Practice Chemistry MCQ
99) Why is sodium borohydride an important reagent in reducing a ketone?
a)
b)
c)
d)
It is good for hydrolysis type reactions
it is a good source of the hydride ion (H-)
It can act as a base
it can act as a free radical initiator.
100) Identify the hybridization of carbon atoms in this molecule
H
H
H
H
C
1
C
2
C
3
H
O
C
4
OH
a) 1- sp3, 2- sp2, 3 – sp2, 4 – sp2
b) 1- sp2, 2- sp2, 3 – sp2, 4 – sp
c) 1- sp3, 2- sp, 3 – sp2, 4 – sp
d) 1- sp, 2- sp2, 3 – sp2, 4 – sp
Page 32 of 32