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Jamb Chemistry 2015

Home » Chemistry jamb past questions » Jamb Chemistry 2015
1
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2
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1

The filter in the cigarette reduce the nicotine construct by

A. burning

B. absorption

C. evaporation

D. absorption

ANS 1

Answer: A

Nicotine is a substance in cigarette which makes difficult to make one stop smoking. This can be derived by burning

2

Which of these require crystallization most?

A. Drug making

B. Cement making

C. Paint making

D. Perfume making

 

ANS 2

Answer: A

Crystallization is required the most in industries where the purity of their products is important e.g in the manufacture of drugs

3

Iron is often galvanized in order to

A. Make it more malleable

B. Remove the impurities unit

C. Protect it against corrosion

D. Render it passive

 

ANS 3

Answer: C

Iron is galvanized with zinc covering to protect it against corrosion. 

4

In the industrial production of H2 is removed by (solution)

A.  washing under pressure

B. drying over phosphorus (V) oxide

C. passing the mixture to the limewater

D. using ammonical copper (I) chlorine

 

ANS 4

Answer: A

 

5

The gas that is most useful in protecting humans against solar marathon is

A. chlorine

B. ozone

C. carbon IV oxide

D. hydrogen sulphur

ANS 5

Answer: B

The ozone layer or ozone shield refers to a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet (UV) radiation

6
ANS 6
7
ANS 7
8
ANS 8
9
ANS 9
10
ANS 10
6

Vulcanization involve the removal of

A. monometer

B. the single bond

C. the double bond

D. a polymer

ANS 6

Answer: C

Vulcanizer is the removal of double bond in a chemical reaction.

7

The acid in electrolysis of water is dilute

A. HNO3

B. CH3COOH

C. H2SO4

D. HCl

ANS 7

Answer: C

 

8

A small quantity of solid ammonium chloride (NH4Cl) texted gently in a test tube, the solid gradually disappear produce two gases. Later, a white cloudy deposit was absence on the cooler part of the test tube. The ammonium chloride is to have undergo

A. distillation

B. sublimation

C. precipitation

D. evaporation

 

ANS 8

Answer: B

Sublimation is the transformation of solid gaseous state without passing through the liquid state

 

 

9

When salt loses its water of crystallization to the atmosphere on exposure, the process is said to be

A. efflorescence

B. deliquescence

C. effervescence

D. fluorescence

ANS 9

Correct Option: A

10

Atomicity of ozone is

A. 1

B. 2

C. 3

D. 4

ANS 10

Answer: C

Ozone means O3 as the atomicity is 3.
11
ANS 11
12
ANS 12
13
ANS 13
14
ANS 14
15
ANS 15
11

Which of the noble gases has the greatest ionization energy

A. He

B. Xe

C. Ar

D. Rr

ANS 11

Answer: A

12

The weakest attractive force that can be observed between two molecules is

A. ionic

B. covalent

C. co-ordinate covalent

D. vander Waals

ANS 12

Answer: D

13

An elements used in production of matches is

A. nitrogen

B. aluminum

C. copper

D. sulphur

ANS 13

Answer: D

14

Cathode rays cause an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the rays

A. are positively charged

B. are negatively charged

C. Have mass

D. travel in straight lines

ANS 14

Answer: D

15

Flow of current in electrolytes is due to the movement of

A. electrons

B. Holes and electron

C. Ions

D. Charges

ANS 15

Answer: C

16
ANS 16
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ANS 17
18
ANS 18
19
ANS 19
20
ANS 20
16

A suitable reagent for distinguish between ethanoic and ethanol is

A. bromine water

B. Fehling’s solution

C. sodium hydrogen trioxocarbonate (iv)

D. Ammoniacal silver trioxonitrate(V)

ANS 16

Answer: C

17

In the discovery of protein, the instrument used is

A. cathode ray tube

B. glass tube and discharge tube

C. discharge tube with terminal cathode

D. discharge tube with central cathode

ANS 17

Answer: D

18

The above orbital diagram shown the electronic configuration of

A. chlorine

B. nitrogen

C. calcium

D. neon

 

ANS 18

Answer: B

Nitrogen has an electronic configuration of 7  =
1s2 2ps2 2p3.

19

Which of the following metals burns with brick red

A. Pb

B. Ca

C. Na

D. Mg

ANS 19

Answer: B

20

In the production of soap, concentrated sodium chloride solution is added to

A. increase the solubility of soap

B. decrease the solubility of the soap

C. saponify the soap

D. emulsify the soap

ANS 20

Answer: B

21
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ANS 24
25
ANS 25
21

A liquid that will dissolve fat is

A. hydrochloric acid

B. calcium hydrochloride

C. kerosene

D.water

ANS 21

Answer: C

 

22

Tartaric acid is used industrially to

A. make baking powder

B. make fruit juice

C. remove rust

D. dry substance

ANS 22

Answer: A

23

P1V1 = P1V1 supports ?

A. Charles’s law

B. Boyles’s law

C. Graham’s law

D. Avogadro’s law

ANS 23

Answer: B

24

A fixed mass of gas a volume of 92cm3 at 3°C. When will be its volume at 18C if the pressure remains constant?

A. 15.3cm3

B. 87.3cm3

C. 2.0cm3

D. 97.0cm3

 

ANS 24

Answer: D

 

V1 ÷ T1 = V2 ÷ T2
T1 = 3 × 273 = 276k
T2 = 18 + 273 = 291k
V1 = 92cm3
V2 = ?
V2 = (V1T2) ÷ T1 = (92 × 291) ÷ 276
= 97.0cm3

25

Which of the following ion’s requires the quantity of electricity for discharge at an electrode

A. 2.0 mole of Q3+

B. 2.5 mole of R2+

C. 3.0 mole of T–

D. 4.0 mole of Y–

ANS 25

Answer: A

2.0 mole of Q3+ ions require the largest quantity of electricity for discharge at an electric.

26
ANS 26
27
ANS 27
28
ANS 28
29
ANS 29
30
ANS 30
26

Hydrogen can be displaced from a lot alkaline solution by

A. Fe

B. Cu

C. Cn

D. Sn

ANS 26

Answer: A

27

Which of the following types of alkanols undergo oxidation to produce alkanoic acids.

I. Primary alkanols
II. Secondary alkanols
III. Tertiary alkanols

A. I, II and III

B. I and II only

C. III only

D. I only

ANS 27

Answer: D

Only primary alkanols undergo oxidation to produce alkanoic acid.

28

Rare gases are suitable because they

A.  are monoatomic

B. form ions easily

C. have duplet or octet electronic configuration in the outermost shells in their atoms

D. are volatile gases

ANS 28

Answer: C

29

A major source of oxide of oxygen is from the burning of

A. coal

B. wood

C. fuel

D. chlorofluorocarbons

ANS 29

Answer: A

30

Which of the activities is commonly used as a nuclear fuel

A. uranium

B. palladium

C. actium

D. thorium

ANS 30

Answer: A

31
ANS 31
32
ANS 32
33
ANS 33
34
ANS 34
35
ANS 35
31

The leachate of a certain ash is used in local soap because it contain

A. sodium chloride and potassium hydroxide

B. sodium hydroxide

C. potassium hydroxide

D. soluble carbonates and hydrogen carbonate

ANS 31

Answer: B

Sodium hydroxide (NaOH) is made suitable or soap production locally.

32

All these are electromagnetic waves except

A. White light

B. Photon

C. X-ray

D. Infrared

 

ANS 32

Answer: B

33

Cu2S(s) + O2(g) = 2CU(s) + SO22(g)

A. +1 to 0

B. 0 to +2

C. +2 to +1

D. 0 to +1

ANS 33

Answer: A

The oxidation number is from h to O as a result of release of sulphur.

34

The number of isomers formed by C6H14 is

A. 4

B. 5

C. 2

D. 3

ANS 34

Answer: B

35

There are basic particles from which matter called be made except

A. Salt

B. Atom

C. Ion

D. Molecule

ANS 35

Answer: A

Salt is a chemical used for varieties of purposes, so it’s not part of matter

36
ANS 36
37
ANS 37
38
ANS 38
39
ANS 39
40
ANS 40
36

The energy value of petrol can be determined by

A. Bomb calorimeter

B. Catalytic cracker

C. Fractionating column

D. Thermometer

ANS 36

Answer: C

37

What volume of 0.5mldm3 H2SO4 will exactly neutralize 20cm3 of 0.1moldm3 NaOH Solution?

A. 2.0cm3

B. 5.0cm3

C. 6.8cm3

D.8.3cm3 

ANS 37

Answer: A

 
2NaOH + H2SO4 → Na2SO4 + 2H2O
CaVa) ÷ (CbVb) = ratio of acid / ratio of base
0.5Va ÷ (0.1 × 20) = ½
Va = 2.0cm3
38

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)

A. CH2O

B. C3H6O3

C. C6H12O6

D. C6H12O3

ANS 38

Correct Option: C

Solution

 

C = 40%, 40/12 = 3.33
H = 6.7%, 6.7/1 = 6.7
O = 53.3%, 53.3/16 = 3.33
C = 3.33/3.33 = 1
H = 6.7/3.33 = 2
O = 3.33/3.33 = 1
(CH2O)n = 180
(12 + 2 + 16)n = 180
30n = 180
n = 6
= C6H12O6

39

An oxidation state of Cr in K2Cr2O7

A. 7

B. 6

C. 5

D. 4

ANS 39

Correct Option: B

Ox no of k=1, Ox no of O =-2

K2Cr2O7 = 0

2(1) + 2 Cr + 7(-2)=0

2 + 2Cr – 14 =0

2Cr  = 14-2 = 12

Cr = 12/2 = 6

 

40

The elements that belong to the third period of periodic table are

A. Li, Be, Al and D

B. Na, P, O and Cl

C. B, C, N, and O

D. N2, Mg, S and Ar

ANS 40

Answer: D

41
ANS 41
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ANS 42
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ANS 43
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ANS 44
45
ANS 45
41

When sugar is dissolve in tea, the reaction is accomplished by

A. positive change

B. negative entropy change

C. no entropy change

D. a minimum entropy change

ANS 41

Answer: C

No entropy change because the sugar will not change the chemical equivalent of the tea.

42

NH3(g) + HCl(s) → NH 4Cl (s)

The entropy change in the system above is

A. positive

B. Zero

C. Negative

D. intermediate

ANS 42

Answer: C

Entropy s is a measure of the degree of disorder or randomness of a substance. The entropy charge in the system is negative ie from gas to solid

43

Detergents are manufacture with strength hydrocarbon chains is to make them

A. soluble

B. biodegradable

C. cheaper

D. foamy

ANS 43

Answer: B

Biodegradable because the straight hydrocarbons are natural and slightly soluble in water.

44

Which of the following results in the fall of acid rain

A. oxide of lead

B. particulate matter

C. oxides of sulphur

D. gaseous hydrocarbon

ANS 44

Answer: C

45

The fuming of kettles is caused by the presence in the water of

A. calcium tetraoxosulphate (IV)

B. calcium hydrogentrionocarbonate (IV)

C. calcium hydroxide

D. calcium trioxocarbonate (IV)

 

ANS 45

Answer: B

46
ANS 46
47
ANS 47
48
ANS 48
49
ANS 49
50
ANS 50
46

A difference between chemical and physical change is that in a chemical change

A. oxygen is consumed

B. heat is supplied

C. the reversible process occurs

D. a new substance is formed

ANS 46

Answer: D

47

According to the kinetic theory an absence in temperature causes the kinetic energy of particles to

A. decrease

B. increase

C. remain constant

D. be zero

ANS 47

Answer: D

48

PCL5(g)= PCL3(g) + Cl2(g)

In the reaction above, a decrease in pressure will

A. Decelerate the reaction

B. Increase yield of Pcl3

C. Increase the yield of Pcl5

D. Accurate the reaction

ANS 48

Answer: B

49

Which of the following gives a precipitation when treated with NaOH Solution?

A. AlCl3

B. NH4Cl

C. Na2CO3

D. CH3COONa

ANS 49

Answer: A

50

Electronic configuration of an elements 13x in the subsidiary energy level is

A. 1s2 2s2 2p6 3s2 3p1

B. 1s2 2s2 2p4 3p1 3s1

C. 1s2 2s2 2p6 3s2 3p3

D. 1s1 2s2 2p6 3s2 3p4

ANS 50

Answer: A

51
ANS 51
52
ANS 52
53
ANS 53
54
ANS 54
55
ANS 55
51

Alloys are best prepared by

A. electroplating

B. Arc-welding

C. reducing and mixture of their metallic

D. cooking a molten of the metals

ANS 51

Answer: D

Alloy is a metal that consist of two or more metals combined together 

52

In countries where the temperature fall below 273k, salt always spilled on the ray road in order to

A. increase the boiling point 

B. increase the density of the ice

C. make the ice impure

D. reduce the freezing point of ice

ANS 52
Answer: Option D
53

What is the volume of energy required to burn 45cm3 of mixture at S.T.P

A. 135.0cm3

B. 150.0cm3

C. 45.0cm3

D. 90.0cm3

ANS 53

Answer: D

CH4(g) + 2O2(g) → 2H2O(g)
1 volume of methane will react with 90cm3 of oxygen at S.T.P

54

The substance that is used in the steel industry for the removal of carbon. Sulphur and phosphorus impurities from pig iron is

A. oxygen

B. chlorine

C. nitrogen

D. hydrogen

ANS 54

Answer: A

55

If glucose is heated on the concentration tetraoxosulphate(iv)acid, it will be dehydrated

A. carbon

B. carbon(iv)oxide

C. ethane

D. ethanol

ANS 55

Answer: A

56
ANS 56
57
ANS 57
58
ANS 58
59
ANS 59
60
ANS 60
56

Rare gases are suitable because they

A. are monoatomic

B. are monoatomic

C. have duplet or octet electronic configuration in the outermost shells in their atoms

D. are volatile gases

ANS 56

Answer : C

57

Which of the following compounds can be represented by the molecular formula C2 H6O?

A. propanal

B. ethanol

C. methanoic acid

D. glucose

 

ANS 57

Answer:  B

58

Two equal bulbs, one containing ammonia and the other one opened mouth-to mouth to each other at temperature the entropy in the mixture of gases is likely to

A. remain unchanged

B. increase

C. decrease

D. charge

 

ANS 58

Answer: A

The bubble remain the same because entropy favors the mixture as it is the degree of randomness or disorderliness.

59

what is the pH of 0.00lmoldm3 solution of sodium hydroxide

A. 14

B. 13

C. 12

D. 11

ANS 59

Answer: D

[H+][OH−] = 10 − 4
[H+] =10 − 14 ÷ [OH+]
=10 −14 ÷ (1 × 10 − 3) = 10 − 11
pH = − log10[H+ ]
= − log10[10 − 11] = − 1 × −11
log10[10 − 11] = 1
= − 1 × 11 × 1
= − 11

60

According to the kinetic theory an absence in temperature causes the kinetic energy of particles to

A. decrease

B. increase

C. remain constant

D. be zero

ANS 60

Answer:  C

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