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JAMB questions for "Chemistry :: chemical combination"
Q1

Calculate the percentage by mass of nitrogen in calcium trioxonitrate(V).

 

[Ca = 40, N = 14, O = 16]

A

17.1%

B

27.6%

C

8.5%

D

13.1%

E
Q2

The droplets of water observed around a bottle of milk taken out of the refrigerator is due to the fact that the 

A

saturated vapour pressure of the milk is equal to the atmospheric pressure

B

water vapour in the air around the bottle loses some of its energy to the bottle

C

water vapour in the air around the bottle gains some energy from the bottle

D

temperature of the milk drops as it loses heat into the surroundings

E
Q3

Calculate the volume of 0.5 mol dm-3 H2SO4 that is neutralized by 25cm3 of 0.1 mol dm-3 NaOH.

A

0.4 cm3

B

0.1 cm3

C

5.0 cm3

D

2.5 cm3

E
Q4

2Na(s) + 2HO(l) → 2NaOH(aq) + H2(g)

 

From the equation above, calculate the mass of sodium hydroxide produced by 2.3g of sodium .

 

[H = 1, O = 16, Na = 23]

A

0.40g

B

0.80g

C

4.00g

D

8.00g

E
Q5

The uncovered raw food that is sold along major roads is likely to contain some amount of 

A

Pb

B

Cu

C

Ag

D

Na

E
Q6

The colour of the fountain water is

A

blue

B

orange

C

red

D

yellow

E
Q7

Lead is used for making bullets and lead shots because of its 

A

resistance to corrosion

B

low melting point

C

high density

D

flexibility

E
Q8

MnO2(s) + xHCl(aq) → MnCl2(aq) + yH2O(l) + zCl2(g)

 

In the equation above, what are the values of x, y and z respectively?

A

4, 1, 2

B

1, 2, 1

C

2, 1, 2

D

4, 2, 1

E
Q9

What is the volume of oxygen required to burn completely 45cm3 of methane at s.t.p?

A

45.0 cm3

B

90.0 cm3

C

135.0 cm3

D

180.0 cm3

E
Q10

Carbon exists naturally in the combined state as

A

graphite

B

coal

C

diamond

D

wood

E
Q11
l.      Treatment of cancerll.     Detection of leakages in water remainslll.    Detection of the ages of ancient toolsIV.    Preparation of drugs   which combination of the above refers to the uses of radioactive isotopes?
A
l, ll and lll
B
l, ll lll and lV
C
ll and lll
D
l and ll
E
Q12
How many moles of limestone will be required to produce 5.6g of CaO?   [Ca = 40, C = 12, O = 16]
A
0.20 mol
B
1.12 mol
C
0.10 mol
D
0.56 mol
E
Q13
if 0.75 mole of cyclopropane and 0.66 mole of oxygen are mixed in a vessel with a total pressure of 0.7 atmosphere, what is the partial pressure of oxygen in the mixture?
A
0.44 atmosphere
B
0.22 atmosphere
C
0.55 atmosphere
D
0.33 atmosphere
E
Q14
A fixed mass of gas has a volume of 92cm3 at 30C. What will be its volume at 18oC if the pressure remains constant?
A
15.3 cm3
B
87.3cm3
C
552.0cm3
D
97.0cm3
E
Q15
Which of the following solutions containing only hydroxyl ions will liberate hydrogen gas when reacted with magnesium metal?
A
1.0 x 10-6 mol dm-3
B
1.0 x 10-12 mol dm-3
C
1.0 x 10-2 mol dm-3
D
1.0 x 10-4 mol dm-3
E
Q16
What is the decrease in volume of air when pyrogallol is shaken with 30.00cm3 of air?
A
0.63 cm3
B
0.06 cm3
C
15.00 cm3
D
6.30 cm3
E
Q17
An element X with relative atomic mass 16.2 contains two isotopes 168X with relative abundance of 90% and m8X with relative abundance of 10%.   The value of m is
A
14
B
12
C
D
18
E
16
Q18
The ratio of the initial to the final pressure of a given mass of gas is 1:1:5. Calculate the final volume of the gas if the initial volume was 300Cm3 at the same temperature.
A
120 cm3
B
200 cm3
C
450 cm3
D
750 cm3
E
Q19
50cm3 of carbon (II) oxide was exploded with 150cm3 of air containing 20% oxygen by volume. Which of the reactants was in excess
A
Carbon (II) oxide
B
Carbon (IV) oxide
C
Oxygen
D
Nitrogen
E
Q20
What is the temperature of a given mass of a gas initially at O0C and 9 atm, if the pressure is reduced to 3 atm at constant volume? 
A
91k
B
182k
C
273k
D
819k
E
Q21
200cm3 each of 0.1 M solutions of lead (II) trioxonitrate (V) and hydrochloric acid were mixed. Assuming that lead (II) chloride is completely insoluble, calculate the mass of lead (II) chloride that will be precipitated   [Pb = 207, Cl = 35.5, N = 14, O = 16]
A
2.78 g
B
5.56 g
C
8.34 g
D
11.12 g
E
Q22
Which of the following gases will diffuse fastest when passed through a porous plug?   [H = 1, C = 12, N = 14, O = 16]
A
Propane
B
Oxygen 
C
Methane
D
Ammonia
E
Q23
30cm3 of hydrogen was collected over water at 27oC and 780 mm Hg. If the vapour pressure of water at the temperature of the experiment was 10 mm Hg, calculate the volume of the gas at 760 mm Hg and 7oC
A
40.0 cm3  
B
35.7 cm3
C
28.4 cm3
D
25.2 cm3
E
Q24
If sulphur (VI) oxide and methane are released simultaneously at the opposite ends of a narrow tube, the rates of diffusion RSO2 and RCH4 will be in the ratio   [S = 32, O = 16, C = 12, H = 1]
A
4 : 1
B
2 : 1
C
1 : 2
D
1 : 4
E
Q25
C3H8(g) +5O2(aq) → 4H2O(g) + 3CO2(g). From the equation above, the volume of oxygen at s.t.p. required to burn 50cm3 of propane is
A
250 cm3
B
150 cm3
C
100 cm3
D
50 cm3
E
Q26
35cm3 of hydrogen was sparked with 12cm3 of oxygen at 1100C and 760mm Hg to produce steam. What percentage of the total volume of gas left after the reaction is hydrogen?
A
11%
B
31%
C
35%
D
69%
E
Q27
An element, X, forms a volatile hydride XH3 with a vapour density of 17.0. The relative atomic mass of X is   [H = 1]
A
34.0
B
31.0
C
20.0
D
14.0
E
Q28
A mixture of 0.20 mole of Ar, 0.020 mole of N2 and 0.30 mole of He exerts a total pressure of 2.1 atms. The partial pressyre of He in the mixture is
A
0.90 atm
B
0.80 atm
C
0.70 atm
D
0.60 atm
E
Q29
Oxygen is a mixture of two isotopes 168O and 188O with relative abundances of 90% and 10% respectively. The relative atomic mass of oxygen is
A
16.0
B
16.2
C
17.0
D
18.0
E
Q30
200cm3 of air was passed over heated copper in a syringe several times to produce copper (II) oxide. When cooled, the final volume of air recorded was 158cm3. estimate the percentage of oxygen in the air.
A
31%
B
27%
C
21%
D
19%
E
Q31
What volume of oxygen will remain after reacting 8 cm3 of hydrogen with 20 cm3 of oxygen?
A
10 cm3
B
12 cm3
C
14 cm3
D
16 cm3
E
Q32
A gas that will turn orange potassium heptaoxodichromate (IV) solution to clear green is
A
sulphur (VI) oxide
B
hydrogen sulphide
C
sulphur (IV) oxide
D
hydrogen chloride
E
Q33
8 g of CH4 occupies 11.2 dm3 at s.t.p. What volume would 22 g of CH3CH2CH3 occupy under the same conditions?   [C = 12, H = 1]
A
3.7 dm3
B
11.2 dm3
C
22.4 dm3
D
33.6 dm3
E
Q34
How many moles of oxygen molecules would be produced from the decomposition of 2.5 moles of potassium trioxochlorate (V)
A
2.50
B
3.50
C
3.75
D
7.50
E
Q35
A balanced chemical equation obeys the law of
A
conservation of mass
B
definite proportions
C
multiple proportions
D
conservation of energy
E
Q36
At 250C atm, a gas occupies a volume of 1.50 dm3. What volume will it occupy at 1000C and 1 atm?
A
1.88 dm3
B
6.00 dm3
C
18.80 dm3
D
60.00 dm3
E
Q37
How many moles of (H+) are there in 1 dm3 of 0.5 M solution of H2SO4?
A
2.0 moles
B
1.0 moles
C
0.5 moles
D
0.25 moles
E
Q38
If 100cm3 of oxygen pass through a porous plug in 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is   [O = 16, H = 1]
A
10.0 s
B
12.5 s
C
17.7 s
D
32.0 s
E
Q39
An increase in temperature causes an increase in the pressure of a gas in a fixed volume due to an increase in the
A
number of molecules of the gas
B
density of the gas molecules
C
number of collisions between the gas molecules and the walls of the container
D
E
Q40
In two separate experiments, 0.86 g and 0.71 g of chlorine combined with a metal X respectively. An analysis showed that Y and Z contain 0.20 g and 0.40 of X respectively. The above represents the law of
A
multiple proportion
B
conversation of mass
C
constant composition
D
reciprocal proportion
E
Q41
A given quantity of a gas occupies a volume of 228 cm3 at a pressure of 750 mm Hg. What will be its volume at atmospheric pressure?
A
220 cm3
B
225 cm3
C
230 cm3
D
235 cm3
E
Q42
Calculate the volume of carbon (VI) oxide measured at s.t.p produced when 1 kg of potassium hydrogen trioxocarbonate (IV) is totally decomposed by heat.   [GMV at s.t.p. = 22.4 dm3 , K = 39, O = 16, C = 12, H = 1]
A
28 dm3
B
56 dm3
C
112 dm3
D
196 dm3
E
Q43
A sample of gas exerts a pressure of 8.2 atm when confined in a 2.93 dm3 container at 200C. The number of moles of gas in the sample is   [R= 0.082 litre atm/deg mole]
A
1.00
B
2.00
C
3.00
D
4.00
E
Q44
In the reaction; SnO2 + 2C → Sn + 2CO, the mass of coke containing 80% carbon required to reduce 0.302 kg of pure tin oxide is   [Sn = 119, O = 16, C = 12]
A
0.40 kg
B
0.02 kg
C
0.04 kg
D
0.06 kg
E
Q45
The avogadro's number of 24 g of magnesium is the same as that of
A
1g of hydrogen molecules
B
16g of oxygen molecules
C
32 g of oxygen molecules
D
35.5 g of chlorine molecules
E
Q46
If a gas occupies a container of volume 146 cm3 at 180C and 0.971 atm, its volume in cm3 at s.t.p. is 
A
133
B
146
C
266
D
292
E
Q47
20.00cm3 of a solution containing 0.53g of anhydrouse Na2CO3 in 100cm3 requires 25.00 of H2SO4 for complete neutralization. The concentration of the acid solution in moles per dm3 is   [H = 1, C = 12, O = 16, Na = 23, S = 32]
A
0.02
B
0.04
C
0.06
D
0.08
E
Q48
The molar ratio of carbon to hyroden of a volatile liquid compound is 1:2. 0. 12g of the liquid on evaporation at s.t.p. gave 32 cm3 of vapour. The molecular formular of the liquid is   [G.M.V = 22.4 dm3, C = 12, H = 1]
A
C3H6
B
C4H8
C
C5H10
D
C6H12
E
Q49
If the quantity of oxygen occupying a 2.76 litre container at a pressure of 0.825 atmospheres and 300K is reduced by one-half, what is the pressure exerted by the remaining gas?
A
1.650 atm.
B
0.825 atm
C
0.413 atm
D
0.257 atm
E
Q50
In the reaction CaC2(s) + 2HO(l) Ca(OH)2(s) + CH2(g) what is the mass of solid calcium carbide needed to produce 1000 cm3 of acetalene gas at S.T.P?   [C = 12, Ca = 40, G.M.V = 22400cm3]
A
3.8 g
B
2.9 g
C
2.0 g
D
1.0 g
E
Q51
The number of atoms of chlorine present in 5.85 g of NaCl is   [Na = 23, Cl = 35.5, Avogadro's number = 6.02 x 1023]
A
6.02 x 1022
B
5.85 x 1023
C
6.02 x 1023
D
5.85 x 1024
E
Q52
How much of magnesium is required to react with 250 cm3 of 0.5 HCl?   [Mg = 24]
A
0.3 g
B
1.5 g
C
2.4 g
D
3.0 g
E
Q53
A white solid suspected to be lead trioxonitrate (V), zinc trioxocarbonate (IV) was heated strongly. Its residue which was yellow when hot and white when cold is
A
lead (II) oxide
B
calcium oxide
C
zinc oxide
D
lead nitrate
E
Q54
Which of the following compounds is NOT formed by the action of chlorine on methane?
A
CH3Cl
B
C2H5Cl
C
CH2Cl2
D
CHCl3
E
Q55
The general formula of an alkyl halide (where X represents the halide) is
A
CnH2n - 2X
B
CnH2n + 1X
C
CnH2n + 2X
D
CnH2n + X
E
Q56
Starch can be converted to ethyl; and alcohol by
A
distillation
B
fermentation
C
isomerization
D
cracking
E
Q57
Some properties of chemical substances are mentioned below(I) sour taste (II) slippery to touch (III) yields alkaline gas with ammonium salts (IV) has pH less than 7 (V) turns phenol-phthalein pink. Which of the above are NOT typical properties of alkalis?
A
I, IV and V
B
IV and V
C
I and IV
D
II and V
E
II, III and V
Q58
Hydrogen is not liberated when trioxonitrate (V) acid reacts with zinc because
A
zinc is rendered passive by the acid
B
hydrogen produced is oxidized to water
C
oxides of nitrogen are produced
D
all nitrates are soluble in water
E
trioxonitrate (V) acid is a strong acid
Q59
A certain industrial pocess is represented by the chemical equation 2A(g) + B(g) ↔ C(g) ΔH = X kJ mol-1. Which of the following conditions will favour the yield of the products?
A
Increase in temperature, decrease in pressure
B
Increase in temperature, increase in pressure
C
Decrease in temperature, increase in pressure
D
Decrease in temperature, decrease in pressure
E
Constant temperature, increase in pressure
Q60
Which of the following is used in the manufacture of bleaching powder?
A
Sulphur dioxide
B
Chlorine
C
Hydrogen tetraoxosulphate(VI)
D
Hydrogen sulphide
E
Nitrogen dioxide