WAEC - Chemistry (2017)

1
Which of the following species determines the chemical properties of an atom?
Answer
(A)
Electron
2
The following glasswares are used to measure the volume of liquids EXCEPT
Answer
(C)
test tube
3
Pauli exclusion principle is related to
Answer
(D)
quantum numbers of electrons
4
The species with no electron in the 3d-orbital is
Answer
(B)
\(Sc^{3+}\)
5
The seperation of Nitrogen from oxygen using fractional distillation of air is possible because
Answer
(C)
of the difference in their boiling points
6
The purity of a solid sample can best be determined by its
Answer
(B)
melting point
7
The mass of one mole of \((NH_{4})_{2}CO_{3}\) is   [O=16.0, N=14.0, C=12.0, H=1.0]
Answer
(D)
96.0g
8
Atomic orbital is
Answer
(B)
a region around the nucleus where electrons are most likely to be found
9
The property of elements which increases down a group of the periodic table is
Answer
(C)
ionic radius
10
The reason for the decrease in the atomic size of elements across a period is that
Answer
(A)
nuclear charge increases while the outermost electrons are drawn closer to the nucleus
11
The oxidation number of nitrogen in \(Pb(NO_{3})_{2}\) is
Answer
(D)
+5
12
Which of the following arrangements indicates the correct decreasing order of ionization energy of period 3 elements?
Answer
(B)
Cl, P, Al, Na
13
Which of the following metals has the strongest metallic bond?
Answer
(A)
\(_{13}Al\)
14
Which of the following substances does not have van der Waals' forces?
Answer
(A)
Copper
15
The oxidation number of X in \(XO_{4}^{3-}\) is
Answer
(D)
+5
16
The ionization energy is affected by the following factors except
Answer
(C)
ability to attract shared electron(s)
17
Which of the following statements is correct?
Answer
(D)
Ionic compounds in solution would conduct electricity
18
The bond angle in tetrahedral molecules such as tetrachloromethane is 
Answer
(B)
109.5°
19
The properties of a good primary standard include the following except
Answer
(B)
low molecular mass
20
The use of diamond in abrasives is due to its
Answer
(B)
hardness
21
Which of the following statements about endothermic reaction is correct?
Answer
(D)
Heat energy is absorbed
22
A 0.1\(moldm^{-3}\) solution of sodium hydroxide was diluted with distilled water to 0.001\(moldm^{-3}\). What is the dilution factor?
Answer
(B)
100.00
23
Graphite and Diamond are similar in that they
Answer
(C)
form carbon(IV) oxide on combustion
24
In a saturated solution at a given temperature, the undissolved solutes are in equilibrium with
Answer
(B)
dissolved solute particles
25
The number of atoms present in 2.5moles of a triatomic gas is equivalent to [1mole = \(6.02\times 10^{23}\)]
Answer
(C)
\(1.5\times 10^{24}\)
26
When Magnesium reacts with oxygen, heat is 
Answer
(C)
evolved and the reaction is exothermic
27
Which of the following gases is not acidic?
Answer
(D)
CO
28
A hydrocarbon contained 14.3% hydrogen. The empirical formula for the hydrocarbon is   [H= 1.0, C= 12.0]
Answer
(B)
\(CH_{2}\)
29
Which of the following statements is NOT a chemical property of an acid?
Answer
(A)
Evolution of ammonia when heated with ammonium salts
30
Halogens generally react with metals to form
Answer
(D)
salts
31
Potassium Chloride solid does not conduct electricity because
Answer
(B)
strong cohesive forces make its ions immobile
32
When water was added to a white anhydrous substance X, the colour changed to blue. X is
Answer
(A)
\(CuSO_{4}\)
33
Solubility curve can be used in the determination of the
Answer
(C)
amount of solid drugs in a given solution
34
If 0.2g of a salt is required to saturate 200\(cm^{3}\) of water at room temperature, what is the solubility of the salt?
Answer
(B)
1.0\(gdm^{-3}\)
35
The property of a chemical reaction that is affected by the presence of a catalyst is
Answer
(A)
activation energy
36
Soluble salts can be prepared by the following methods except
Answer
(C)
double decomposition
37
Chemical reactions occurs when the colliding reactants have energy that is
Answer
(B)
greater than the activation energy
38
The common feature of reactions at the anode is that
Answer
(C)
oxidation is involved
39
Consider the following reaction equation: \(2NO_{(g)} + O_{{2}{(g)}} \to 2NO_{{2}{(g)}}\). What is the change in the oxidation number of nitrogen?
Answer
(C)
+2 to +4
40
Which of the following factors characterize members of the same homologous series?
Answer
(D)
Successive members undergo changes in molecular formula by \(CH_{2}\)
41
Calculate the mass of copper deposited if a current of 0.45A flows through \(CuSO_{4}\) solution for 1hour 15mins.   [Cu=64.0, S= 32.0, O =16.0, 1F= 96500C]
Answer
(B)
0.67g
42
Classification of alkanols is based on the 
Answer
(D)
number of alkyl groups bonded to the carbon having the hydroxyl group
43
The name of the compound \(C_{4}H_{9}COOC_{3}H_{7}\) is
Answer
(A)
propyl pentanoate
44
Which of the following pairs of gases are pollutants from car exhaust?
Answer
(C)
Carbon(II) oxide and Sulphur(IV) oxide
45
Fats and oils can be obtained from any of the following sources except
Answer
(A)
paraffin oil