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Chemistry Past Questions

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137 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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137 questions

Question 1 of 20 137 total questions

Question 41

jamb 2018

An element X forms the following compounds with chlorine; XCl\(_4\), XCl\(_3\), XCl\(_2\). This illustrates the

Alaw of multiple proportions

Blaw of chemical proportions

Claw of simple proportions

Dlaw of conservation of mass

View Explanation & Discuss

Question 42

jamb 2018

The knowledge of half-life can be used to

ACreate an element

BDetect an element

Cto combine elements

DIrradiate an element

View Explanation & Discuss

Question 43

jamb 2018

The figure above shows the electrolysis of molten sodium chloride. Z is the

Aanode where the Cl\(^-\) ions are oxidized

Bcathode where the Cl\(^-\) ions are reduced

Canode where the Na\(^+\) ions are reduced

Dcathode where the Na\(^+\) ions are oxidized

View Explanation & Discuss

Question 44

jamb 2018

Which of the following produces relatively few ions in solution?

ANaOH

BCa(OH)\(_2\)

CKOH

DAI(OH)\(_3\)

View Explanation & Discuss

Question 45

jamb 2018

The choice of method for extracting a metal from its ores depends on the

Astrength of the core

Bposition of the metal in the electrochemical series

Csource of the core

Dposition of the metal in the periodic table

View Explanation & Discuss

Question 46

jamb 2018

Calculate the pH of 0.05 moldm\(^{-3}\) H\(_2\)SO\(_4\)

A1.30

B1.12

C1.00

D0.30

View Explanation & Discuss

Question 47

jamb 2018

What mass of Cu would be produced by the cathodic reduction of Cu\(^{2+}\) when 1.60A of current passes through a solution of CuSO\(_4\) for 1 hour. (F=96500Cmol\(^{-1}\) , Cu=64)

A7.64g

B3.82g

C1.91g

D0.96g

View Explanation & Discuss

Question 48

jamb 2018

The solubility of the solids that dissolves in a given solvent with the liberation of heat will

Aincrease with an increase in temperature

Bdecrease with an increase in temperature

Cdecrease with a decrease in temperature

Dnot be affected by changes in temperature

View Explanation & Discuss

Question 49

jamb 2018

The constituent common to duralumin and alnico is

ACo

BMn

CAl

DMg

View Explanation & Discuss

Question 50

jamb 2018

The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;

Asaponification

Bdehydration

Cesterification

Dhydrolysis

View Explanation & Discuss

Question 51

jamb 2018

Diamond is a bad conductor of electricity because its bonding electrons are used in

Acrystal lattice formation

Bcovalent bond formation

Cmetallic bond formation

Dcoordinate bond formation

View Explanation & Discuss

Question 52

jamb 2018

To what volume must 300cm\(^3\) of 0.60M sodium hydroxide solution be diluted to give a 0.40M solution?

A450cm\(^3\)

B300cm\(^3\)

C200cm\(^3\)

D150cm\(^3\)

View Explanation & Discuss

Question 53

jamb 2018

In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

A5cm\(^3\)

B10cm\(^3\)

C20cm\(^3\)

D50cm\(^3\)

View Explanation & Discuss

Question 54

jamb 2018

Which of the following is used to power steam engines?

Alubricating oil

Bcoal

Cbitumen

Ddiesel oil

View Explanation & Discuss

Question 55

jamb 2018

2KClO\(_3\)(s) → 2KCl(s) + 3O\(_2\)(g)
The importance of the catalyst in the reaction above is that

Aheating may not be required before the reaction takes place

Bthe reaction is controllable even at a high temperature

Cthe reaction produces large quantity of oxygen

Dthe reaction takes place more rapidly at a lower temperature

View Explanation & Discuss

Question 56

jamb 2018

In the laboratory preparation of oxygen, the gas cannot be collected by downward displacement of air because

Athe density of oxygen is greater than that of air

Bthe density of air is nearly the same as that of oxygen

Coxygen is a component of air

Dair is an impure substance

View Explanation & Discuss

Question 57

jamb 2018

When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;

Anitrogen and carbondioxide

Bthe rare gases

Cnitrogen and oxygen

Dnitrogen and the rare gases

View Explanation & Discuss

Question 58

jamb 2018

A balanced chemical equation obeys the law of

Aconservation of mass

Bdefinite proportions

Cmultiple proportions

Dconservation of energy

View Explanation & Discuss

Question 59

jamb 2018

Which of the following are mixtures?
I. Petroleum
II. Rubber latex
III. Vulcanizer's solution
IV. Carbon sulphide

AI, II and III

BI, II and IV

CI and II only

DI and IV

View Explanation & Discuss

Question 60

jamb 2018

The refreshing and characteristic taste of soda water and other soft drinks is as a result of the presence of

Acarbon(IV)oxide

Bcarbon(ll)oxide

Csoda

Dglucose

View Explanation & Discuss

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