JAMB Chemistry 1994 Past Questions and Answers

Chemistry JAMB 1994 Q4 ✓ Answer: D

8 g CH4 occupies 11.2dm3 at s.t.p. What volume would 22 g of CH3CH2CH occupy under the sme condition?

A

3.7 dm3

B

11.2 dm3

C

22.4 dm3

D

33.6 dm3 [ C= 12, H =1]

Chemistry JAMB 1994 Q5 ✓ Answer: D

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

A

298 K

B

546 K

C

819K

D

1092 K

Chemistry JAMB 1994 Q6 ✓ Answer: B

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

A

The mass of the gas

B

The vapour density of the gas

C

The volume of the gas

D

The temperature of the gas

Chemistry JAMB 1994 Q7 ✓ Answer: C

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

A

0.1

B

0.5

C

2.0

D

4.0

Chemistry JAMB 1994 Q8 ✓ Answer: B

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

A

it decreases the number of Collision between the molecules

B

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

C

it increase the number of Collision between the molecules

D

it causes the molecules to combine

Chemistry JAMB 1994 Q9 ✓ Answer: D

The shape of ammonia molecules is

A

trigonal planar

B

octahedral

C

square planar

D

tetrahedral.

Chemistry JAMB 1994 Q11 ✓ Answer: D

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

A

Atomic radius

B

Ionic radius

C

Electropositivity

D

Electronegativity. Nucleus An Electron The diagram above represents atom of

Chemistry JAMB 1994 Q13 ✓ Answer: C

Elements X, Y and Z belongs to groups 1,V and V11 respectively. Which of the following is TRUE about the bond types of XZ and YZ

A

Both are electrovalent

B

Both are covalent

C

XY is electrovalent and YZ3 is covalent

D

XZ is covalent and YZ3 is electrovalent.

Chemistry JAMB 1994 Q14 ✓ Answer: B

Which of the following atoms represents deuterium? ‘ No of No of No of protons neutrons electrons

A

1

B

1

C

1

D

1

Chemistry JAMB 1994 Q15 ✓ Answer: B

The set-up above would be useful for determining the amount of

A

Oxygen in air

B

Water vapour in air

C

CO2 in air

D

Argon in air.

Chemistry JAMB 1994 Q18 ✓ Answer: B

Sodium chloride has no solubility product value because of its.

A

saline nature

B

high solubility

C

low solubility

D

insolubility

Chemistry JAMB 1994 Q19 ✓ Answer: D

The solubility in moles per dm3 of 20.2g of potassium trioxonitrate (V) dissolved in 100g of water at room temperature is

A

0.10

B

0.20

C

1.00

D

2.00 [K = 39, O = 16, N = 14]

Chemistry JAMB 1994 Q21 ✓ Answer: B

Which of the following compounds is a base?

A

CO2

B

CaO

C

H3PO3

D

CH3COOH

Chemistry JAMB 1994 Q23 ✓ Answer: D

What volume of oxygen measured at s.t.p would be liberated on electrolysis by 9650 coulombs of electricity?

A

22.4 dm3

B

11.2 dm3

C

1.12 dm3

D

0.560 dm3 [Molar Volume of gas = 22.4 dm3, F = 96,500 C mol-1]

Chemistry JAMB 1994 Q24 ✓ Answer: B

Crude copper could be purified by the electrolysis of concentrated copper911) chloride if the crude copper is

A

made both the anode and the cathode

B

made the cathode

C

made the anode

D

dissolved in the solution. [PAGE 42]

Chemistry JAMB 1994 Q25 ✓ Answer: B

H-(s) + H2O(1) H2(g) + OH-(aq). From the equation above, it can be inferred that the

A

reaction is a double decomposition

B

hydride ion is reducing agent

C

hydride ion is an oxidizing agent

D

reaction is neutralization. The H for the reaction represented by the energy profile above is

Chemistry JAMB 1994 Q27 ✓ Answer: C

An anhydride is an oxide of a non-metal.

A

Which will not dissolve in water

B

whose solution water has pH greater than7

C

whose solution in water has a pH less than 7

D

whose solution in ware has a pH of 7

Chemistry JAMB 1994 Q28 ✓ Answer: A

MnO4(aq) + 8H +(aq) + Fe2+(aq) Mn2+(aq) +5Fe3+ + 4H2O(1). The oxidation number of manganese in the above reaction change from

A

+7 to +2

B

+6 to +2

C

+5 to +2

D

+4 to +2

Chemistry JAMB 1994 Q30 ✓ Answer: B

Which of the following is TRUE of Le Chatelier’s principle for an exothermic reaction?

A

Increase in temperature will cause an increase in equilibrium constant

B

Increase in temperature will cause a decrease in the equilibrium constant

C

Addition of catalyst will cause an increase in the equilibrium constant.

Chemistry JAMB 1994 Q31 ✓ Answer: A

Which of the following are produced when ammonium trioxonirate(V) crystals are cautiously heated in a hard glass round bottomed flask?

A

N2O and steam

B

NO2 and ammonia

C

N2O4 and NO2

D

NO and NO2

Chemistry JAMB 1994 Q32 ✓ Answer: C

2HCl(aq) + CaCO3(s) CaCl2(aq) + H2O(10 + CO2g). From the reaction above, which of the following curves represents the consumption of calcium trioxocarbonate(lV) as dilute HCl is added to it?

A

L

B

M

C

N

D

P

Chemistry JAMB 1994 Q33 ✓ Answer: C

In the diagram above, R is a mixture of

A

potassium tetraoxochlorate(Vii) and concentrated H2SO4

B

potassium tetraoxomanganate (vii) and concentrated HCl

C

manganese(1V) oxide and concentrated HCl

D

manganese (1V) oxide and concentrated HCl

Chemistry JAMB 1994 Q34 ✓ Answer: D

Which of these metals CANNOT replace hydrogen from alkaline solutions?

A

Aluminium

B

Zinc

C

Tin

D

Iron

Chemistry JAMB 1994 Q35 ✓ Answer: D

Clothes should be properly rinsed with water after bleaching because

A

the bleach decolourizes the clothes

B

chlorine reacts with fabrics during bleaching

C

the clothes are sterilized during bleaching

D

hydrogen chloride solution is produced during bleaching. [PAGE 43]

Chemistry JAMB 1994 Q36 ✓ Answer: B

Which of these solutions will give a white precipate with a solution of barium chloride acidified with hydrochloride acid?

A

Sodium trioxocarbonate(1V)

B

Sodium tetraoxosulphate

C

Sodium trioxosulphate (1V)

D

Sodium sulphides

Chemistry JAMB 1994 Q37 ✓ Answer: A

SO3 is NOT directly dissolved in water in the preparation of H2SO4 by the contact process because.

A

the reaction between SO3 and water is violently exotheremic

B

acid is usually added to water and never water to acid

C

SO3 is an acid not dissolve in water readily

D

SO3 is an acid gas.

Chemistry JAMB 1994 Q38 ✓ Answer: A

In an electrolytic set-up to protect iron from corrosion, the iron is

A

made the cathode

B

made the anode

C

used with a metal of lower electropositive potential

D

initially coated with tin

Chemistry JAMB 1994 Q39 ✓ Answer: C

Which of the following is NOT true of metals?

A

They are good conductors of electricity

B

They ionize by electron loss

C

Their oxides are acidic

D

They have high melting points.

Chemistry JAMB 1994 Q40 ✓ Answer: B

Which of the following is the correct order of decreasing activity of the metal Fe, Ca, Al and Na?

A

Fe > Ca > Al > Na

B

Na > Ca > Al > Fe

C

Al > Fe > Na > Ca

D

Ca > Na > Fe > Al.

Chemistry JAMB 1994 Q41 ✓ Answer: D

H CH3 H H H¯C ¯ C¯ C P- C H CH3 H The IUPAC name of the compound above is

A

2,2-dimethyl but-1-yne

B

2,2-dimethyl but-1-ene

C

3,3-dimethyl but-1-ene

D

3,3-dimethyl but-1-yne

Chemistry JAMB 1994 Q43 ✓ Answer: D

When sodium is added to ethanol, the products are

A

sodium hydroxide and water

B

sodium hydroxide and hydrogen

C

sodium ethnocide and water

D

sodium ethnocide and hydrogen.

Chemistry JAMB 1994 Q44 ✓ Answer: B

The general formula of alkanones is

A

RCHO

B

R2CO

C

RCOOH

D

RCOOR

Chemistry JAMB 1994 Q45 ✓ Answer: A

When sodium ethanoate is treated with a few drops of concentrated tetraoxosulphate(V1) acid one of the products is

A

CH3COOH

B

CH3COOH3

C

CH3COOC2H5

D

C2H4COOCH

Chemistry JAMB 1994 Q46 ✓ Answer: B

One mole of a hydrocarbon contains 48 g of carbon. If its vapour density is 28, the hydrocarbon is

A

an alkane

B

an alkene

C

an alkyne

D

aromatic [C= 12, H = 1] Use the diagram below to answer questions 47 and 48. The reaction taking place in flask G is known as

Chemistry JAMB 1994 Q48 ✓ Answer: B

The caustic soda solution in the conical flask serves to

A

dry ethene

B

remove carbon (1V) oxide from ethene

C

remove carbon (11) oxide from ethene

D

remove sulphur (1V0 oxide from ethene.

Chemistry JAMB 1994 Q49 ✓ Answer: D

Which of the represents Saponification?

A

reaction of carboxylic acids with sodium hydroxide

B

reaction of Alkanoates with acids

C

reaction of carboxylic acids with sodium alcohols

D

reaction of Alkanoates with sodium hydroxide.

Chemistry JAMB 1994 Q49 ✓ Answer: C

Which of the following orbital of carbon are mixed with hydrogen in methane?

A

1s and 2p

B

1s and 2s

C

2s and 2p

D

2s and 3p

Chemistry JAMB 1994 Q50 ✓ Answer: D

The confirmatory test for Alkanoic acids in organic qualitative analysis is the

A

turning of wet blue litmus paper red

B

reaction with alkanols to form esters

C

reaction with sodium hydroxide to foem salt and water

D

reaction with aqueous Na2CO3 to liberate a gas which turns lime water milky.

Chemistry JAMB 1994 Q50 ✓ Answer: B

Which of the following reagents will confirm the presence of instaurations in a compound?

A

Fehling’s solution

B

Bromine water

C

Tollen’s reagent

D

Benedict’s solution [PAGE 44] Chemistry 1995

JAMB Chemistry 1994 past questions