🧪 1991

JAMB Chemistry 1991 past questions

39 questions from the 1991 JAMB UTME Chemistry paper. Free, with answers where available.

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Chemistry JAMB 1991 Q1 ✓ Answer: A
Which of the following can be obtained by fraction of distillation?
A
Nitrogen from liquid air
B
Sodium chloride for sea water
C
Iodine from a solution of iodine in carbon tetrachloride
D
Sulphur from a solution of sulphur in carbon disulphide.
Chemistry JAMB 1991 Q2 ✓ Answer: A
Which of the following are mixture? I Petroleum ii Rubber latex. Iii Vulcanizes’ solution. Iv Carbon (ll) sulphides
A
I, ii and iii
B
I, ii and iv
C
I and ii only
D
I and iv
Chemistry JAMB 1991 Q3 ✓ Answer: B
An iron ore is known to contain 70.0% Fe2O3. The mass of iron metal which can theorically be obtained from 80kg of the ore is.
A
35.0 kg
B
39.2 kg
C
70.0 kg
D
78.4 kg [Fe = 356, O = 16]
Chemistry JAMB 1991 Q4 ✓ Answer: A
In two separate experiments 0.36 g and 0.71 g of chlorine combine with a metal X to give Y and Z respectively. An analysis showed that Y and Z contain 0.20 g and 0.40 g of X respectively. The data above represents the law of .
A
multiple proportion
B
conversation of mass
C
constant composition
D
reciprocal proportion.
Chemistry JAMB 1991 Q5 ✓ Answer: C
30cm3 of oxygen at 10 atmosphere pressure is placed in a 20 dm3 container. Calculate the new pressure it temperature is kept constant.
A
6.7 atm
B
15.0 atm
C
6.0 atm
D
66.0 atm
Chemistry JAMB 1991 Q7 ✓ Answer: C
Calculate the volume of carbon (lv) oxide measure at s.t.p, produced when 1 kg of potassium hydrogen trioxocarbonate (iV) is totally decomposed by heat.
A
28 dm3
B
56 dm3
C
112 dm3
D
196 dm3 [G.M.V at s.t.p = 22.4 dm3, K = 39, O = 16, C = 12, H = 1]
Chemistry JAMB 1991 Q9 ✓ Answer: A
Atoms of element X (with 2 electrons in the outer shell) combine with atoms of Y( with 7 electrons in the outer shell). Which of the following is FALSE? The compound formed
A
has formula XY
B
is likely to be ionic
C
contains X2+ ions
D
contains Y- ions
Chemistry JAMB 1991 Q10 ✓ Answer: C
The ions X- and Y+ are isoelectronic, each containing a total of 10 electrons. How many proteins are in the nuclei of the neutral atoms of X and Y respectively?
A
10 and 10
B
9 and 9
C
11 and 9
D
9 and 11
Chemistry JAMB 1991 Q12 ✓ Answer: C
Which of the following represents the type of bonding present in ammonium chloride molecule?
A
Ionic only
B
Covalent only
C
Ionic and dative covalent
D
Dative covalent only.
Chemistry JAMB 1991 Q13 ✓ Answer: B
Which of the following is arranged in order of increasing electronegativity?
A
Chlorine, aluminium, magnesium, phosphorus, sodium.
B
Sodium, magnesium, aluminium phosphorus, chlorine
C
Chlorine, phosphorus, aluminium, magnesium, sodium.
D
Sodium, chlorine, phosphorus, magnesium, aluminium.
Chemistry JAMB 1991 Q15 ✓ Answer: B
The electrons of two atoms of Y and Z are arranged in shells as shown above. The bond formed between the atoms of Y and Z is
A
ionic
B
covalent
C
dative
D
metallic.
Chemistry JAMB 1991 Q16 ✓ Answer: B
Which of the following ionsis a pollutant in drinking water even in trace amount?
A
Ca2+
B
Hg2+
C
Mg2+
D
Fe2+
Chemistry JAMB 1991 Q20 ✓ Answer: C
50 cm3 of sulphur (lV) oxide, 800cm3 of ammonia, 450 cm3 of hydrogen chloride, 1.0 cm3 of water at 15oC. Which of the following is suitable for demonstrating the fountain experiment?
A
Sulphur (lV) oxide and hydrogen chloride
B
Carbon (lV) oxide and ammonia
C
Ammonia and hydrogen chloride
D
Carbon (lV) oxide and sulphur (1V) oxide [PAGE 32]
Chemistry JAMB 1991 Q21 ✓ Answer: C
Which of the following substances could be satisfactorily used as X in the above figure?
A
Ammonia and Potassium hydroxide
B
Potassium hydroxide and sodium chloride
C
Ammonia and ethanoic acid
D
Ethanoic and sodium chloride
Chemistry JAMB 1991 Q22 ✓ Answer: A
What volume of CO2 at s.t.p would be obtained by reacting 10cm3 of 0.1 M solution of anhydrous sodium trioxocarbonate (lV) with excess acid?
A
2.240 cm3
B
22.40 cm3
C
224.0 cm3
D
2240 cm3 [G.M.V at s.t.p = 22.4 dm3
Chemistry JAMB 1991 Q24 ✓ Answer: C
Which of the following equivocal solutions, Na2CO3, Na2SO4, FeCl3, NH4Cl and CH3 COONa, have pH greater than?
A
FeCl3 and NH4Cl
B
Na2CO3 CH3 COONa and Na2SO4,
C
Na2CO3 and CH3 COONa
D
FeCl3 , CH3, COONa. NH4Cl
Chemistry JAMB 1991 Q26 ✓ Answer: B
2H2(g) + SO2(g) 3S(s) + 2H2O(1). The above reaction is
A
a redox reaction in which H2S is the oxidant and SO2 is the reductant.
B
a redox reaction in which SO2is the oxidant and H2S is the reductant.
C
Not a redox reaction because there is no oxidant in the reaction equation
D
Not a redox reaction because there is no reductant in the reaction equation.
Chemistry JAMB 1991 Q27 ✓ Answer: C
Manganese(lV) oxide is known to hasten the decomposition of hydrogen peroxide. Its main actions is to.
A
increase the surface area of the reactants
B
increase the concentration of the reactants
C
lower the activation energy for the reaction
D
lower the heat of reaction, H, for the reaction,
Chemistry JAMB 1991 Q28 ✓ Answer: A
1.1 g of CaCl2 dissolved in 50 cm3 of water caused a rise in temperature of 34oC. The heat reaction, H for CaCl2 in kJ per moles is
A
-71.1
B
–4.18
C
+17.1
D
+111.0 [Ca = 40, Cl = 35.5, specific heat of water is 4.18 KJ-1
Chemistry JAMB 1991 Q29 ✓ Answer: A
NO + CO 1/2 N2 + CO2 H = -89.3kJ .What conditions would favour maximum conversion of nitrogen (ll) oxide and carbon(ll) oxide in the reaction above?
A
low temperature and high pressure
B
high temperature and low pressure
C
high temperature and high pressure
D
low temperature and low pressure.
Chemistry JAMB 1991 Q30 ✓ Answer: B
Which of the following equilibria is unaffected by a pressure change?
A
2NaCl 2Na + Cl2
B
H2 + I2 2HI
C
2O3 3O2
D
2NO2 N2O4
Chemistry JAMB 1991 Q31 ✓ Answer: C
Initial concentration of no in moles Initial Rate (moles / sec) 0.001 3.0 x 10-5 0.002 1.2 x 10 -4 The data in the table above shows the rate of reaction of nitrogen (ll) oxide with chlorine at 25oC. It can be concluded that doubling the intial concentration of NO increase the rate of reaction by factor of
A
two
B
three
C
four
D
five
Chemistry JAMB 1991 Q32 ✓ Answer: C
Which of the following gases will rekindle a brightly glowing splint?
A
NO2
B
NO
C
N2O
D
Cl2
Chemistry JAMB 1991 Q33 ✓ Answer: A
Which of the following salts can be melted without decomposition?
A
Na2CO3
B
CaCO3
C
MgCO3
D
ZnCO3
Chemistry JAMB 1991 Q34 ✓ Answer: C
Oxygen gas can be prepared by heating
A
ammonium trioxonirate (V)
B
ammonium trioxonirate (lll)
C
potassium trioxonirate (V)
D
manganese (lV) oxide. [PAGE 33]
Chemistry JAMB 1991 Q35 ✓ Answer: C
The appropriate test paper to use in the above experiment is moist.
A
litmus paper
B
potassium heptaoxodichromate (1V) paper
C
lead (11)trioxonirate (V) paper.
D
Universal indicator paper.
Chemistry JAMB 1991 Q36 ✓ Answer: C
Addition of aqueous ammonia to a solution of Zn++ gives a white precipitate which dissolves in an excess of ammonia because.
A
zinc is amphoteric
B
zinc hydroxide is readily soluble
C
zinc forms a complex which is readily soluble in excess ammonia
D
ammonia solution is a strong base.
Chemistry JAMB 1991 Q37 ✓ Answer: C
Which of the following, in clear solution, forms a white precipitate when carbon(1V) oxide is bubbled into it for a short time?
A
KOH
B
NaOH
C
Ca(OH)2
D
Al(OH)3
Chemistry JAMB 1991 Q38 ✓ Answer: B
Copper (11) tetraoxosulphate (V1) is widely used as a
A
Fertilizer
B
Fungicide
C
Disinfectant
D
Purifier
Chemistry JAMB 1991 Q39 ✓ Answer: C
Which of the following metals can be prepared in samples by the thermal decomposition to their trioxonirate (V) salt?
A
Copper and mercury
B
Silver and copper
C
Mercury and silver
D
Magnesium and mercury
Chemistry JAMB 1991 Q40 ✓ Answer: B
Which of the following compounds can exist as geometric isomers?
A
2-methylbut2-ene
B
But-2-ene
C
But-1-ene
D
H Cl — C—Br H
Chemistry JAMB 1991 Q42 ✓ Answer: C
The final products of the presence of ultraviolet light are hydrogen chloride and
A
chloromethane
B
tetrachloromethane
C
trichloromethane
D
dichloromethane
Chemistry JAMB 1991 Q43 ✓ Answer: B
How many grams of bromine will be required to completely react with 10 g of propyne?
A
20 g
B
40 g
C
60 g
D
80 g [C = 12, H = 1, Br = 80].
Chemistry JAMB 1991 Q44 ✓ Answer: A
Ethene when passed into concentrated H2SO4 is rapidly absorbed. The product is diluted with water and then warmed to produce.
A
ethanol
B
diethyl ether
C
ethanal
D
diethyl sulphate.
Chemistry JAMB 1991 Q45 ✓ Answer: C
One of the advantages of detergents over soap is that detergents.
A
are easier to manufacture
B
foam more than soap
C
form soluble salts with hard water
D
are able to deter germ more than soap.
Chemistry JAMB 1991 Q46 ✓ Answer: B
CH3CH2 CHCH3 alc.KOH CH3CH = CHCH3 X CHCH3 + CH3CH2CH =CH2 The above reaction is an example of
A
dehydration
B
dehydrohalogenation
C
neutralization
D
a fission reaction
Chemistry JAMB 1991 Q48 ✓ Answer: B
The compound. CH3¯CH¯CH3 sCH2Cl Is known as
A
1-chloro-2-methylbutane
B
1-chloro-2-methylpronane
C
2-chloromethylethane
D
1-chloro-2,2-dimethylethane
Chemistry JAMB 1991 Q49 ✓ Answer: A
Which of the following statements is TRUE of the complete hydrolysis of a glyceride by sodium hydroxide?
A
3 moles of NaOH are required for each mole of glyceride
B
3 moles of glycerol are produced
C
only one mole of soap is formed.
D
Concentrated H2SO4 is essential for the completion of the reaction. [PAGE 34]
Chemistry JAMB 1991 Q50 ✓ Answer: A
Which of the following are the products of the reaction between CH3COOH and Cl2 in sunlight?
A
ClCH2COOH + HCl
B
CH3COCl + HOCl
C
CH3COOCl + HCl
D
CH3COCl + H2O Chemistry 1992