UME 1978 CHEMISTRY QUESTIONS
1. Which of the following statements
is correct? A. The average kinetic energy of a gas is directly proportional to
its temperature, B. At constant temperature, the volume of a gas increase as
the pressure increases, C. the pressure of a gas is inversely proportional to
its volume, D. the temperature of a gas is directly proportional to its volume,
E. the collisions of molecules with each other are inelastic
2. The molarity of a 2% by weight of aqueous solution of H2SO4 (molecular weight = 98) is A. 4.55 B. 3.55 C. 2.55 D. 1.55 E. 0.55
3. Zinc
Oxide is a? A. basic oxide, B. acidic oxide, C. amphoteric oxide D. neutral
oxide, E reactive oxide
4. When
sodium chloride and metallic sodium are each dissolved in water A. Both
processes are exothermic B. both processes are endothermic C. the dissolution
of metallic sodium is endothermic, D. the dissolution of metallic sodium is
exothermic, E. the dissolution of sodium chloride is explosive.
5. The
periodic classification of the elements is an arrangement of the elements in
order of their A. atomic weights B. isotopic weights, C. molecular weights, D.
atomic numbers, E. atomic masses
6. In
the reaction between sodium hydroxide and sulphuric acid solutions, what volume
of 0.5 molar sodium hydroxide would exactly neutralize 10cm3 of 1.25
molar sulphuric acid? A. 5cm3, B. 10cm3, C. 20cm3,
D 25cm3, E. 50cm3
7. A
small quantity of solid ammonium chloride (NH4CI) was heated gently in a test
tube; the solid gradually disappeared to produce a mixture of two gases. Later
a white cloudy deposit was observed on the cooler part of the test-tube. The
ammonium chloride is said to have undergone
A. distillation, B. Sublimation C. precipitation, D. Evaporation , E.
decomposition
8. Elements
P, Q, R, S, have 6, 11, 15 and 17 electrons respectively, therefore, A. P will
form an electrovalent bond with R, B. Q will form a covalent bond with S, C. R
will form an electrovalent bond with S, D. Q will form an electrovalent bond
with S, E. Q will form a covalent bond with R.
9. An
element X forms the following compounds with chlorine: XCI4, XCI3,
XCI2. This illustrates the A. Law of multiple proportions, B. law of
chemical proportions C. law of simple proportion, D. law of conservation of
mass, E. law of definite proportions
10. The
oxidation state of chlorine in potassium chlorate is A. +1 B. +2 C. +3, D. +5
E. +7
11. When
air, which contains the gases: oxygen, nitrogen, carbon dioxide, water vapour
and the rare gases, is passed through alkaline pyrogallol and then over
quicklime, the only gases left are A. nitrogen and carbon dioxide, B. the rare
gases C. nitrogen and oxygen, D. nitrogen and the rare gases, E. nitrogen,
carbon dioxide and the rare gases
12. When
heat is absorbed during a chemical
reaction, the reaction is said to be A. thermodynamic, B. Exothermic C.
Isothermal, D. endothermic E. thermostatic
13. When
large hydrocarbon molecules are heated at high temperature in the presence of
catalyst to give smaller molecules, the process is known as A. disintegration,
B. polymerization, C. isothermal, D. endothermic, E. thermostatic
14. The
pH of four solutions W, X, Y, Z are 4, 6, 8, 10, respectively therefore, A.
none of these solutions is acidic, B. the pH of Y is made acidic by addition of
distilled water, C. Z is the most acidic solution, D. W is the most acidic
solution, E. X is neutral.
15. When
each of the nitrates of potassium, magnesium and iron is heated, A. all the
nitrates decompose to their oxides, B. the nitrate of magnesium gives the
nitrite and oxygen, C. the nitrates of magnesium and iron give the oxides, D.
the nitrate of iron gives the nitrite and oxygen, E. the nitrate of magnesium
is not decomposed.
16. Which
of the following metals cannot replace hydrogen from water or steam? A. Sodium,
B. Magnesium, C. Iron, D. Calcium, E. Copper
17. A
sample of hard water contains some calcium sulphate and calcium hydrogen
carbonate. The total hardness may therefore be removed by: A. boiling the
water, B. adding excess calcium hydroxide, C. adding a calculated amount of
calcium hydroxide, D. adding sodium carbonate, E. adding magnesium hydroxide
18. During
the electrolysis of copper (II) sulphate between platinum electrodes, if litmus
solutions is added to the anode compartment, A. the litmus turns blue but no
gas is evolved, B. the litmus turns blue and oxygen is evolved, C. the litmus
blue and hydrogen is evolved, D. the litmus turns red and oxygen is evolved, D.
the litmus turns red and then becomes colourless
19. The
reaction between an organic acid and an alcohol in the presence of an acid
catalyst is known as: A. saponification, B. dehydration, C. estreification, D.
Hydrolysis, E. hydration.
20. The
IUPAC names for the compounds CH2COOH and CH2 = CH2
are respectively: A. acetic acid and ethane, B. ethanoic acid and ethane, C.
methanoic acid and ethylene, D. ethanol and ethane, E. acetic acid and
ethylene.
21. If
30cm3 of oxygen diffuses through a porous pot in 7 seconds, how long
will it take 60cm3 of chlorine to diffuse through the same pot, if
the vapour densities of oxygen and chlorine are 16 and 36 respectively? A. 9.3
sec, B. 14sec, C. 21sec, D. 28sec, E. 30.3sec
22. Brass
and Bronze are both metallic alloys. Which of the following constituents is
common to both alloys? A. Tin, B. Zinc, C. Copper, D. Lead, E. Aluminum
23. Which
of the following gases may not be dried with concentrated sulphuric acid? A.
HCl, B. N2 C. Cl2, D. SO2, E. NH3
24. Which
of the following reactions does not take place in the smelting of iron in a
blast furnace? A. CaCO3(s)
CaO(S) + CO2(g), B. C(s)
+ 2O2(g)
CO2(g), C. 3Fe(s) + 2O2(g)
FeO4(s), D. SiO2(s) +
CaO(s
CaCO3(s), E. CO2(g) + C(s)
2CO(g)
25. Which
of the following is not a member of the homologous series of the paraffins
(alkanes)? A. C3H8, B. C5H12, C. C2H16,
D. C15H32, E. C24H48
26. When
ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is
called A. ionic bond, B. electrovalent bond, C. Covalent bond, D. Co-ordinate
bond, E. Hydrgen bond.
27. An
example of an alcohol is A. CCl4, B. CH3COOH, C. CHCl3,
D. C2H6, E. CH3OH.
28. The
nucleus of an atom contains A. Protons only, B. Neutrons only, C. protons and
electrons, D. neutrons and electrons, E. protons and neutrons
29. Hypochlorous
acid is used as a bleach because A. it is strong acid, B. it yields chlorine
readily in pure water, C. it is an oxidizing agent, D. it is weak acid, E. it
is a reducing agent
30. The
normal boiling point of a liquid is defined as A. the temperature at which its
vapour pressure equals the atmospheric pressure, B. the temperature at which
bubbles begin to form, C. the temperature at which the vapour pressure equals 1
atmosphere, D. the temperature at which the rate of condensation of vapour
equals the rate of vaporization of the liquid, E. the temperature at which the
space above the liquid is saturated.
31. Which
of the following compounds will form a solution if exposed to the air? A. Na2CO3.10H2O,
B. NaNO3, C. CuSO4, D. CaCl2, E. Na2SO4.10H2O
32. The
most common type of chemical reaction which alkanes undergo is A. Substitution,
B. Addition, C. Condensation, D. polymerization, E. double decomposition
33. Consider
the following exothermic reaction 2SO2(g) + O2(g)
2SO 3(g)
A. the reaction rate increases, B. Concentration of SO3 decreases,
C. concentration of SO3 increases, D. SO2 gas becomes unreactive, E. O2 gas
becomes unreactive.
34. If
excess zinc is added to a bluish green solution of copper (II) sulphate, and
the excess zinc filtered off after completion of reaction, a colourless
solution is obtained because A. both zinc and copper are metals, B. the
sulphate radical and the zinc ion are divalent, C. zinc is more electro
positive than copper, D. both zinc and copper form dispositive ions in
solution, E. zinc is a reducing agent.
35. Three
solutions contain carbonate, sulphate and sulphide ions respectively. One test
that will identify just ONE of them completely is by addition to each of them
of A. barium chloride solution, B. dilute hydrochloric acid, C. lead nitrate
solution, D. calcium chloride solution, E. sodium hydroxide solution
36. Two
gas cylinders contain ethylene (ethene) and acetylene respectively. One test
which can be used to distinguish between them is by A. passing each gas through
bromine water, B. passing each gas through dilute potassium permanganate
solution, C. passing each gas through silver nitrate solution, D. passing each
gas through ammoniacal copper(1)chloride solution, E. treating each gas
catalytically with excess hydrogen gas.
37. Consider
the following equation: H2O + 2Fe2++Cl2 ⇌2Fe3+ + 2CI-
+ H2O. The only ion which behaves as an oxidizing agent is A. Fe2+,
B. Cl2, C. Fe3+, D. Cl-, E. H2O
38. If
hydrogen sulphide gas is passed into a solution of a pure iron chloride, a
yellow deposit appears. If the deposit is filtered, a pale green solution is
left behind. The pale green solution is A. dilute sulphuric acid, B. dilute
hydrochloric acid, C. unreacted hydrogen sulphide in water, D.
iron(III).chloride, E. iron(II)chloride
39. Which
one of the following changes is physical? A. adding iron fillings to aerated
water, B. adding sodium metal to water, C. cooling a solution of iron (II) sulphate
to obtain the hydrated salt, D. cooling water to obtain ice, E. burning the
domestic gas (Utilgas) for cooking
40. By
means of filtration, one component can be obtained pure from an aqueous mixture
of sodium chloride and A. potassium nitrate, B. sand, C. lead nitrate, D. sugar
(glucose), E. Starch
41. Five
atoms T,W,X,Y,Z consist of the following practices:
|
|
T
|
W
|
X
|
Y
|
Z
|
|
Proton
|
13
|
16
|
17
|
19
|
20
|
|
Electron
|
13
|
16
|
17
|
19
|
20
|
|
Neutron
|
14
|
16
|
35
|
20
|
20
|
Which of the five have the following properties: relative atomic
mass is greater than 30 but less than 40, it has odd atomic number and forms a
unipositive ion in solution? A. T, B. W, C. X, D. Y, E. Z.
42. A
solid X when heated gives off a brown gas. If X is soluble in excess sodium
hydroxide solution but insoluble in excess ammonium hydroxide solutions, then X
is A. basic lead carbonate, B Lead(II)nitrate, C. sodium carbonate, D. zinc
nitrate, E. sodium nitrate
43. Consider
the solubility curves of three salts X, Y and Z given in the diagram below. If each
solution of the salt contains 200g, and is heated to 1000C, which
solution or solutions will deposit more than 100g of the solute when suddenly
cooled to 00C?
44. An
experimental test of the law of conservation of Mass is illustrated in the
diagram. In practice, the flask is weighed before and after reaction between
solutions X and Y. which of the following pairs of solutions will be unsuitable
for the experiment? A. X = hydrochloric acid; Y = Silver nitrate, B. X = barium
chloride; Y = Dilute sulphuric acid, C. X = Hydrochloride acid; Y = sodium
hydroxide, D. X = Hydrochloric acid; Y = Lead nitrate, E. X = Hydrochloric
acid; Y = sodium carbonate
45. In
titration involving sodium hydroxide solution and dilute hydrochloric acid,
where would you place the base? A. in the breaker, B. in the conical flask, C.
in the burette, D. in the standard flask, E. in the measuring cylinder
46. A
gas jar was inverted over burning yellow phosphorus floating over water in a
breaker. After burning, the water level was found to rise in the gas jar. The
water level rises because. A. Pressure inside the gas jar is greater than
pressure outside it, B. the air in the gas jar had been used up by burning, C.
oxygen in the gas jar had been used up by burning, D. nitrogen in the gas jar
had been used up by burning, E. the temperature in the jar had risen
considerably
47. You
are provided with five gas jars containing SO2, CO2, H2,
CO, and NO respectively. Select a test from A to E which will identify ANY ONE
of the gases completely. A. Pass each gas into lime water, B. pass each gas
into water and test with litmus paper, C. pass each gas into concentrated
sulphuric acid, D. expose each gas to atmospheric air, E. expose each gas to
fumes of hydrogen chloride.
48. Which of the following substances would you use as an indicator in the titration of sodium carbonate solution against hydrochloric acid (complete neutralization)? A. Litmus paper, B. phenolphthalein, C. methyl orange, D. Universal indicator, E. none of these.
49. Five
compound R, T, W, X, and Y form following compounds: a basic hydride RH, an
acidic hydride YH, amphoteric oxide W2O3, XO2
which of the elements is an alkali? A. R, B. T, C. W, D. X, E. Y
50. The
sizes (diameters) of five atoms are in the order R<T<W<X<Y, Y being
largest. If each atom has an electron situated on its circumference, and
neglecting other factors, which of the atoms will lose its electron most
reluctantly? A. R, B. T, C. W, D. X, E Y
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