JAMB - Chemistry (2019)

1
A secondary alkanol can be oxidized to give an?
Answer
(A)
alkanone
2
Which of the following will give a precipitate with an aqueous solution of copper (I) chloride?
Answer
(D)
But-1-yne
3
The IUPAC name for CH\(_3\)CH\(_2\)COOCH\(_2\)CH\(_3\) is
Answer
(C)
ethylpropanoate
4
A certain hydrocarbon on complete combustion at s.t.p produced 89.6dm\(^3\) of CO\(_2\) and 54g of water. The hydrocarbon should be?
Answer
(D)
C\(_4\)H\(_6\)
5
2-methylprop-1-ene is an isomer of?
Answer
(C)
but-2-ene
6
Hydrocarbons which will react with Tollen's reagent conform to the general formula
Answer
(C)
C\(_n\)H\(_{2n - 2}\)
7
The IUPAC name of the compound CF\(_3\)CHBrCl is
Answer
(B)
2-bromo-2-chloro-1,1,1-trifluoroethane
8
A synthetic rubber is not obtained from the polymerization of?
Answer
(D)
hexane
9
Burning magnesium ribbon in air removes which of the following
(i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?
Answer
(C)
i only
10
Which of the following is the best starting material for the preparation of oxygen? Heating of trioxonitrate (v) with
Answer
(A)
Pb
11
Which of the following metals is the most essential in the regulation of blood volume, blood pressure and osmotic equilibrium?
Answer
(C)
Sodium
12
Which of the following alkaline earth metals react more spontaneously with water?
Answer
(D)
Strontium
13
When chlorine water is exposed to bright sunlight, the following products are formed
Answer
(C)
HCl\(_{(aq)}\) and O\(_2\)
14
Which process(es) is/are involved in the turning of starch iodide paper blue-black by chlorine gas?
Answer
(C)
chlorine oxidizes the iodide ion to produce iodine which attacks the starch to give the blue-black color
15
Which of the following is a set of neutral oxides?
Answer
(A)
N\(_2\)O, H\(_2\)O, CO
16
SO\(_3\) is not directly dissolved in water in the industrial preparation of H\(_2\)SO\(_4\) by the contact process because
Answer
(C)
The reaction between SO\(_3\) and water is violently exothermic
17
Which of the following statements does not show Rutherford's account of Nuclear Theory? An atom contains a region
Answer
(D)
which is very large and in which close to 98% of projectiles pass undeflected
18
Elements X and Y have electronic configurations 1s\(^2\)2s\(^2\)2p\(^4\) and 1s\(^2\)2s\(^2\)2p\(^6\)3s\(^2\)3p\(^1\) respectively. When they combine, the formula of the compound formed is
Answer
(C)
Y\(_2\)X\(_3\)
19
By what amount must the temperature of 200cm\(^3\) of Nitrogen at 27°C be increased to double the pressure if the final volume is 150cm\(^3\) (Assume ideality)
Answer
(A)
150°C
20
The combustion of carbon(II)oxide in oxygen can be represented by equation:
 2CO + O\(_2\) → 2CO\(_2\)
Calculate the volume of the resulting mixture at the end of the reaction, if 50cm\(^3\) of carbon(ii)oxide was exploded in 100cm\(^3\) of oxygen
Answer
(B)
125cm\(^3\)
21
When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called
Answer
(D)
covalent bond
22
Which of the following represents the kind of bonding present in ammonium chloride?
Answer
(C)
ionic and covalent
23
Consider the reaction
A\(_{(s)}\) + 2B\(_{(g)}\) → 2C\(_{(aq)}\) + D\(_{(g)}\)
What will be the effect of a decrease in pressure on the reaction?
Answer
(C)
rate of backward reaction will increase
24
For the general equation of the nature
xP + yQ ⇌ mR + nS, the expression for the equilibrium constant is
Answer
(D)
\(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\)
25
Which of the following reactions is an oxidation process?
Answer
(B)
2O\(^{2-}\) + 4e\(^-\) \(\to\) O\(_2\)
26
If acidified Potassium Dichromate(VI) (K\(_2\)Cr\(_2\)O\(_7\)) acts as oxidizing agent, color changes from
Answer
(B)
orange to green
27

The heat of formation of ethene, C\(_2\)H\(_4\) is 50 kJmol\(^{-1}\), and that of ethane, C\(_2\)H\(_6\) is -82kJmol\(^{-1}\). Calculate the heat evolved in the process:

C\(_2\)H\(_4\) + H\(_2\) \(\to\) C\(_2\)H\(_6\)

Answer
(B)
-132kJ
28
Which of the following statements about catalyst is false?
Answer
(D)
catalysts do not alter the mechanism of the reaction and never appear in the rate low
29
Which of the following does not support the fact that air is a mixture?
Answer
(D)
none of the above
30
What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)?
Answer
(A)
Fractional crystallization
31
At 27°C, 58.5g of sodium chloride is present in 250cm\(^3\) of a solution. The solubility of sodium chloride at this temperature is?
(molar mass of sodium chloride = 111.0gmol\(^{-1}\))
Answer
(A)
2.0 moldm\(^{-3}\)
32
Which of the following properties increases from left to right along the period but decreases down the group in the Periodic Table?
i. Atomic Number ii. Ionization energy  iii. Metallic character  iv. Electron affinity
Answer
(B)
ii and iv only
33
The molecular shape and bond angle of water are respectively
Answer
(D)
bent, 105°
34

Na\(_2\)CO\(_3\) + 2HCl \(\to\) 2NaCl + H\(_2\)O + CO\(_2\)

The indicator most suitable for this reaction should have a pH equal to

Answer
(C)
3
35
A radioactive nucleus has a half-life of 20 years, starting with 100,000 particles, how many particles will be left exactly at the end of 40 years
Answer
(C)
25,000 particles
36
Which two gases can be used for the demonstration of the fountain experiment?
Answer
(C)
HCl and NH\(_3\)
37
Which of the following pollutants will lead to the depletion of ozone layer?
Answer
(A)
chlorofluorocarbon
38
Which of the following describes the chemical property of acids?
Answer
(D)
Acid + X\(_n\)CO\(_3\) \(\to\) Salt + H\(_2\)O + CO\(_2\)
39
Which of the following pairs cannot be represented with a chemical formula?
Answer
(A)
air and bronze
40

Consider the equation below:

Cr\(_2\)O\(_7 ^{2-}\) + 6Fe\(^{2+}\) + 14H\(^{+}\) \(\to\) 2Cr\(^{3+}\) + 6Fe\(^{3+}\) + 7H\(_2\)O.

The oxidation number of chromium changes from

Answer
(B)
+6 to +3
41
Which of the following is a physical change?
Answer
(D)
Freezing ice cream
42
In the reaction between sodium hydroxide and tetraoxosulphate (VI) solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralize 10cm\(^3\) of 1.25 molar tetraoxosulphate (vi) acid?
Answer
(D)
50cm\(^3\)
43
Sulphur exists in six forms in the solid state. This property is known as
Answer
(B)
Allotropy
44
In the reaction:
M + N → P
ΔH = +Q kJ

Which of the following would increase the concentration of the product?
Answer
(C)
Increasing the temperature
45
A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180. Find the molecular formula.
[H = 1, C = 12, O = 16]
Answer
(C)
C\(_6\)H\(_{12}\)O\(_6\)
46
The IUPAC nomenclature of the compound
H\(_3\)C - CH(CH\(_3\)) - CH(CH\(_3\)) - CH\(_2\) - CH\(_3\)
Answer
(B)
2,3- dimethyl pentane
47
Which of the following gases contains the least number of atoms at s.t.p?
Answer
(D)
7 moles of argon
48
What mass of magnesium would be obtained by passing a current of 2 amperes for 2 hours 30 mins, through molten magnesium chloride?
[1 faraday = 96500C, Mg = 24]
Answer
(D)
2.00g
49
Which important nitrogen-containing compound is produced in Haber's process?
Answer
(A)
NH\(_3\)
50
Elements in the periodic table are arranged in the order of their
Answer
(A)
atomic numbers
51
What volume of 0.100M sodium trioxonitrate (V) solution contains 5g of solute ?
[Na = 23, N = 14, O = 16]
Answer
(C)
0.588 litres
52
The two ions responsible for hardness in water are
Answer
(A)
Ca\(^{2+}\) and / or Mg\(^{2+}\)
53
Which of the following could not be alkane?
Answer
(C)
C\(_7\)H\(_{14}\)
54
The electronic configuration of element Z is 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\). What is the formula of the compound formed between Z and tetraoxosulphate (VI) ion.
Answer
(D)
Z\(_2\)(SO\(_4\))\(_3\)
55
The hybridization in the compound \(CH_3 - CH_2 - C \equiv H\) is
Answer
(A)
sp\(^3\) and sp
56
The following are isoelectronic ions except
Answer
(C)
Si\(^{2+}\)
57

Consider the reaction: A + 2B\(_{(g)} \rightleftharpoons \) 2C + D\(_{(g)}\) (\(\Delta\)H = +ve)

What will be the effect of decrease in temperature on the reaction?

Answer
(A)
Rate of backward reaction will increase
58
A cell shorthand notation can be written as A / A\(^+\) // B\(^{2+}\) /B. The double slash in the notation represents the 
Answer
(C)
salt bridge
59
The shapes of water, ammonia, carbon (iv) oxide and methane are respectively
Answer
(B)
angular, pyramidal, linear and tetrahedral
60
Which quantum divides shells into orbitals?
Answer
(C)
Azimuthal
61
The oxidation state(s) of nitrogen in ammonium nitrite is/are
Answer
(A)
-3, +3
62
Hydrogen bond is a sort of
Answer
(A)
van der waals force
63
Methane is prepared in the laboratory by heating a mixture of sodium ethanoate with soda lime. The chemical constituent(s) of soda lime is/are
Answer
(A)
Ca(OH)\(_2\) and NaOH
64
Which of the following sets of operation will completely separate a mixture of sodium chloride, sand and iodine?
Answer
(A)
addition of water, filtration, evaporation to dryness and sublimation
65
200cm\(^3\) of 0.50mol/dm\(^3\) solution of calcium hydrogen trioxocarbonate (IV) is heated. The maximum weight of solid precipitated is
Answer
(A)
10g
66
Which of the following conditions will most enhance the spontaneity of a reaction?
Answer
(A)
\(\Delta\)H is negative and greater than T\(\Delta\)S
67
X is a substance which liberates CO\(_2\) on treatment with concentrated H\(_2\)SO\(_4\). A warm solution of X can decolorize acidified KMnO\(_4\). X is
Answer
(D)
H\(_2\)C\(_2\)O\(_4\)
68
The velocity, V of a gas is related to its mass, M by (k = proportionality constant)
Answer
(B)
V = \(\frac{k}{M^{\frac{1}{2}}}\)
69
The emission of two successive beta particles from the nucleus \(^{32} _{15} P\) will produce
Answer
(C)
\(^{32} _{17}\)Cl
70
Hydrogen diffused through a porous plug
Answer
(C)
four times as fast as oxygen
71

If the cost of electricity required to discharge 10g of an ion X\(^{3+}\) is N20.00, how much would it cost to discharge 6g of ion Y\(^{2+}\)?

[1 faraday = 96,500C, atomic masses are X = 27, Y = 24]

Answer
(D)
N9.00
72
The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?
[X = 63, Y = 27, 1F = 96,500C]
Answer
(C)
N63.00
73
How many alkoxyalkanes can be obtained from the molecular formula C\(_4\)H\(_{10}\)O?
Answer
(D)
3
74
The reaction \(2H_2 S + SO_2 \to 3S + 2H_2 O\) is
Answer
(D)
a redox reaction in which SO\(_2\) is the oxidant and H\(_2\)S is the reductant
75
A solution X, on mixing with AgNO\(_3\) solution gives a white precipitate soluble in aqueous NH\(_3\), a solution Y, when also added to X, also gives a white precipitate which is soluble when heated solutions X and Y respectively contain
Answer
(C)
Pb\(^{2+}\), Cl\(^-\)