Chemistry Past Questions

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Past Questions

2,505 questions
Question 1 of 20 2,505 total questions
Question 1151
jamb 1982

In the reaction N2(g) + O(g)
↔ 2NO(g) produced i an increase in the total pressure will?

Acause less nitrogen to be produced in the equilibrium mixture
Bcause less nitric oxide to be produced in the equilibrium mixture
Ccause more nitric oxide to be produced in the equilibrium mixture
Dcause more oxygen to be produced in the equilibrium mixture
Ehave no effect
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Question 1152
jamb 1982

Which of the following CANNOT be obtained by fractional distillation of petroleum?

AEther
BMethane
CButane
DEthene
EHydrogen
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Question 1153
jamb 1982

In the reaction NH3 + H+ → NH4+, the bond formed results from?

Aan electron transferred from NH3 + H+
Ban electron pair donated by NH3
Can electron pair equally shared
Dan electron pair donated by H+
Ean electron tarnsferred from H+ to NH3
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Question 1154
jamb 1982
Which of the following statements is incorrect?
ACalcium reacts with water to form calcium
BMagnesium reacts very slowly with water but faster with warm water
CIron will not react with water in the absence of air
DSodium reacts with water
ECopper reacts with steam
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Question 1155
jamb 1982
Sodium carbonate crystals on exposure to a dry atmosphere change to a white powder. This phenomenon is known as?
Adeliquescence
Bhygroscopy
Coxidation
Defforescence
Esublimation
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Question 1156
jamb 1982

The product formed at the the cathode during the electrolysis of sodium chloride solution with carbon electrodes is?

Asodium
Bchlorine
Chydrogen
Dsodium hydroxide
Eoxygen
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Question 1157
jamb 1982

Which of the following types of reactions takes place between C2H6 and the halogens?

ASubstitution
BPolymerization
CAddition
DSaponification
EOxidation
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Question 1158
jamb 1982
Cotton is almost pure?
Astarch
Bprotein
Canimal fibre
Dcelluose
Emineral fibre
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Question 1159
jamb 1982
Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is?
Acalcium
Bcalcium oxide
Ccalcium carbide
Dsodium peroxide
Esodium sulphate
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Question 1160
jamb 1982
An amphoteric oxide is an?
Aamorphous oxide of a metal
Bamorphous oxide of a non-mental
Coxide that is insoluble in water
Doxide that behaves both as a base as well as an acid
Eoxide that loses its oxygen on sublimation
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Question 1161
jamb 1982
Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes?
AOxygen gas is given off at the cathode
BHydrogen gas is given of at the anode
CSodium metals is deposited at the anode
DSodium metal is deposited at the cathode
EAAlkalinity at the cathode increases
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Question 1162
jamb 1982
An acid is said to be weak if?
Aits ions are so completely dissociated that they easily drift apart
Bthe acid is not corrosive
Cthe acid has low specific gravity
Dits ions move very slowly when in solution
Eits ions are incompletely dissociated
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Question 1163
jamb 1981
Which of the following represents a precipitation reaction?
AH2SO4 + NaCl \(\to\) NaHSO4 + HCl
BFe +H2SO4 \(\to\) FeSO4 + H2
C4HCl + MnO2 \(\to\) MnCl2 + 2H2O + Cl2
DNa2SO4 + pb(NO3) \(\to\) PbSO4 + 2NaNO
ECuO +2HCl \(\to\) Cl2 + H2O
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Question 1164
jamb 1981

The IUPAC name for

A1-methlpentane
B3-methylbutane
C2-methylbutane
D1-dimethylpropane
E2-methylpentane
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Question 1165
jamb 1981
The general formula of an alkyl halide (which represent the halide) is?
ACnH2n - 2X
BCnH2n + 1X
CCnH2n + 2X
DCnH2nX
ECnH2n - 1
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Question 1166
jamb 1981

An efflorescent compound is a substance that?

Aabsorbs water froom the air without dissolving in it
Bis capable of giving off coloured luminosity
Cgives out water to the atmosphere
Dabsorbs water from the air and dissolves in it
Egives out its water of crystallization on heating
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Question 1167
jamb 1981
The scale formation in a kinetic used for boiling water is caused by the presence in water of?
Acalcium sulphate
Bcalcium carbonate
Ccalcium hydrogen carbonate
Dcalcium hydroxide
Emagnesium sulphate
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Question 1168
jamb 1981

What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?

AAll the nitrate will decompose to their respective metals
BThe nitrates of calcium and potassium will decomposes to their nitrites
COnly copper nitrate decomposes to the metal
DOnly the nitrates of zinc and copper will decompose to their oxides
EThe nitrates of calcium, zinc and copper decompose to their oxides
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Question 1169
jamb 1981
4g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q.
Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?
AThere were more aluminium atoms in Q than P
BThe heat given off in retarded the reaction
CQ generated more pressure than P during the reaction
DP generated more pressure than Q
EQ has a greater surface area for the reaction than P
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Question 1170
jamb 1981
If one mole of aluminium contains 6 x 1023 atoms of aluminium, how many atoms are contained in 0.9g of aluminium?
(Al = 27)
A1.0 x 1021
B6.6 x 1021
C2.0 x 1022
D1.0 x 1022
E5.4 x 1023
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