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Chemistry Past Questions

Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.

4,306 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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4,306 questions

Question 1 of 20 4,306 total questions

Question 1661

jamb 1994

20 cm\(^3\) of a 2.0 M solution of ethanoic acid was added to excess of 0.05 M sodium hydroxide. The mass of the salt produced is?

(Na = 23, C = 12, O = 16, H = 1)

A2.50 g

B2.73 g

C3.28 g

D4.54 g

View Explanation & Discuss

Question 1662

jamb 1994

Which of the following compounds is a base?

ACO₂

BCaO

CH₃PO₃

DCH₃COOCH₃

View Explanation & Discuss

Question 1663

jamb 1994

A few drops of concentrated HCI are added to about 10cm3 of a solution of pH 3.4. The pH of the resulting mixtures is?

Aless than 3.4

Bgreater than 3.4

Cunaltered

Dthe same as that of pure water

View Explanation & Discuss

Question 1664

jamb 1994

Which of the following atoms represents deuterium?

ANo protons = 1, No of neutrons = 0, No of electrons = 0

BNo protons = 1, No of neutrons = 0, No of electrons = 1

CNo protons = 1, No of neutrons = 1, No of electrons = 1

DNo protons = 1, No of neutrons = 2, No of electrons = 1

View Explanation & Discuss

Question 1665

jamb 1994

The solubility, in moles per dm3 of 20.2 g of potassium trioxonitrate (V) dissolve in 100 g of the resulting mixture is?

(K = 39, O = 16, N =14).

A0.10

B0.20

C1.00

D2.00

View Explanation & Discuss

Question 1666

jamb 1994

Sodium chloride has no solubility product value because of its?

Asaline nature

Bhigh solubility

Clow solubility

Dinsolubility

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Question 1667

jamb 1994

A major effect of oil pollution in coastal waters is the?

Adestruction of marine life

Bdesalination of the water

Cincrease in the acidity of the water

Ddetoxification of the water

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Question 1668

jamb 1994

A solid that absorbs water from he atmosphere and forms an aqueous solution is?

Ahydrophilic

Befforescent

Cdeliquescent

Dhygroscopic

View Explanation & Discuss

Question 1669

jamb 1994

Element X, Y and Z belong to a groups I, V and VII respectively. Which of the following is TRUE about the bond types of XZ and YZ₃?

ABoth are electrovalent

BBoth are covalent

CXZ is electrovalent and YZ₃ is covalent

DXZ is covalent and YZ₃ is electrovalent

View Explanation & Discuss

Question 1670

jamb 1994

Which of the following physical properties decreases down a group in the periodic table?

AAtomic radius

BIonic radius

CElectropositivity

DElectronegativity

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Question 1671

jamb 1994

The number of electrons in the valence shell of an element of atomic number 14 is?

View Explanation & Discuss

Question 1672

jamb 1994

An increase in temperature causes an increase in the pressure of a gas because?

Ait decreases the number of collision between the molecules

Bthe molecules of the gas bombard the walls of the container more frequently

Cit increases the number of collision between the molecules

Dit causes the molecules to combine

View Explanation & Discuss

Question 1673

jamb 1994

The shape of ammonia molecule is?

Atrigonal planar

Boctahedral

Csquare planar

Dtetrahedral

View Explanation & Discuss

Question 1674

jamb 1994

The densities of two gases, X and Y, are 0.5 g dm^-3 and 2.0 dm^-3 respectively.
What is the rate of diffusion of X relative to Y?

A0.1

B0.5

C2.0

D4.0

View Explanation & Discuss

Question 1675

jamb 1994

For a gas, the relative molecular mass is equal to 2Y. What is Y?

AThe mas of the gas

BThe vapour density of the gas

CThe volume of the gas

DThe temperature of the gas

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Question 1676

jamb 1994

To what temperature must a gas 273 K be heated in order to double both its volume and pressure?

A298 K

B546 K

C819 K

D1092 K

View Explanation & Discuss

Question 1677

jamb 1994

8g CH4 occupies 11.2 dm3 at s.t.p. What volume would 22 g of CH3CH2CH3 occupy under the same condition?

(C = 12, H = 1)

A3.7 dm³

B11.2 dm³

C22.4 dm³

D33.6 dm³

View Explanation & Discuss

Question 1678

jamb 1994

At the same temperature and pressure, 50 cm³ of nitrogen gas contains the same number of molecules as?

A25 cm³ of methane

B40 cm³ of hydrogen

C50 cm³ of ammonia

D100 cm³ of chlorine

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Question 1679

jamb 1994

A pure solid usually melts?

Aover a wide range of temperature

Bover a narrow range of temperature

Cat a lower temperature than the impure one

Dat the same temperature as the impure one

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Question 1680

jamb 1994

A mixture of sand, ammonium chloride and sodium chloride is best separated by?

Asublimation followed by addition of water and filteration

Bsublimation followed by addition of water and evaporation

Caddition of water followed by filtration and sublimation

Daddition of water followed by crystallization and sublimation

View Explanation & Discuss

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