JAMB Chemistry 1983 Past Questions and Answers

Chemistry JAMB 1983 Q1 ✓ Answer: C

X is crystalline salt of sodium. Solution of X in water turns litmus red produces a gas which turns lime water milky when added to sodium carbonate. With barium chloride solution, X gives a white precipitate which is insoluble in dilute hydrochloric acid. X is

A

Na2,CO3

B

NaHCO3 C NaHSO4 D Na2SO3

E

Na2SO4

Chemistry JAMB 1983 Q1 ✓ Answer: D

Sodium chloride may be obtained from brine by

A

titration

B

decantation

C

distillation

D

evaporation

E

sublimation

Chemistry JAMB 1983 Q2 ✓ Answer: B

The alkanol obtained from the production of soap is

A

ethanol

B

glycerol

C

methanol

D

propanol

E

glycol

Chemistry JAMB 1983 Q2 ✓ Answer: E

FeSO4+ H2S FeS + H2SO4 FeCl + CI2 2FeCL3 FeCl3 + SnCI2 2FeCL2 + SnCI4

A

1 only

B

2 only

C

3 only

D

1 and 3

E

2 and 4.

Chemistry JAMB 1983 Q2 ✓ Answer: D

20cm3 of hydrogen gas are sparked with 20cm3 of oxygen gas in an eudiometer at 373K (100oC) and 1 at atmosphere. The resulting mixture is cooled to 298 K (25oC) and passed over calcium chloride. The volume of the residual gas is

A

40cm3

B

20cm3

C

30cm3

D

10cm3

E

5 cm3

Chemistry JAMB 1983 Q3 ✓ Answer: D

The flame used by welders in cotton metals is

A

butane gas flame

B

acetylene flame

C

kerosene flame

D

oxy-acetylene flame

E

oxygen flame

Chemistry JAMB 1983 Q4 ✓ Answer: B

Consecutive members of an alkane homologous series differ by

A

CH

B

CH2

C

CH3

D

CnHn

E

CnH2n+2

Chemistry JAMB 1983 Q5 ✓ Answer: D

If an element has the lectronic configuration 1s2 2s2 2p6 3s2 3p2, it is

A

a metal

B

an alkaline earth metal

C

an s-block element

D

a p-block element

E

a transition element

Chemistry JAMB 1983 Q8 ✓ Answer: A

Compound W is

A

a soap

B

an oil

C

an alkane

D

an ester

E

sucrose

Chemistry JAMB 1983 Q9 ✓ Answer: A

The molecular formula of X is

A

C12H22O11

B

C6H12O6

C

C3H6O3

D

C7H14O7

E

C4H3O4

Chemistry JAMB 1983 Q10 ✓ Answer: C

reaction of X with yeast forms the basic of the

A

plastic industry

B

textile industry

C

brewing industry

D

soap industry

E

dyeing industry.

Chemistry JAMB 1983 Q12 ✓ Answer: B

Which of the following relationships between the pressure P, the volume V and the temperature T, represents and ideal gas behaviors?

A

P & VT

B

P & T/V

C

PT & V

D

PV & VT

E

P & V/T

Chemistry JAMB 1983 Q13 ✓ Answer: C

In the above experiment (fig1) the litmus paper will initially

A

be bleached

B

turn green

C

turn red

D

turn blue

E

turn black [PAGE 3]

Chemistry JAMB 1983 Q14 ✓ Answer: C

The colour imparted to a flame by calcium ion is

A

green

B

blue

C

brick-red

D

yellow

E

lilac

Chemistry JAMB 1983 Q15 ✓ Answer: D

In the reaction M + N P; H = + Q kJ. Which of the following would increase the concentration of the product?

A

Decreasing the concentration of N

B

Increasing the concentration of P

C

Adding a suitable catalyst.

D

Decreasing the temperature

Chemistry JAMB 1983 Q17 ✓ Answer: D

Fig.2 In the above experiment (fig.2), a current was passed for 10 minutes and 0.63 g of copper was found to be deposited on the cathode of CuSO4 cells. The weight of AgNO3 cell during the same period would be [Cu = 63, Ag –108]

A

0.54 g

B

1.08 g

C

1.62 g

D

2.16 g

E

3.24 g

Chemistry JAMB 1983 Q18 ✓ Answer: E

In the reaction Fe + Cu2+ Fe2+ + Cu, iron displaces copper ions to form copper. This is due to the fact that

A

iron is in the metallic form while dthe copper is in the ionic form

B

the atomic weight of copper is greater than that of ion

C

copper metal has more electrons than ion metal

D

iron is an inert metal

E

iron is higher in the electrochemical series than copper.

Chemistry JAMB 1983 Q19 ✓ Answer: A

C2H5 C =CH2 CH3 The correct name of the compound with the above structural formula is

A

2-methylbut-1-ene

B

2-methylbut-2-ene

C

2-methylbut-1-ene

D

2-ethyprop-1-ene

E

2-ethylprop-2-ene

Chemistry JAMB 1983 Q22 ✓ Answer: A

Sodium decahydrate (Na2SO4 10H2O) an exposure to air loses all its water of crystallization. The process of loss is known as

A

Efflorescence

B

Hygroscopy

C

Deliquescence

D

Effervescence

E

Dehydration

Chemistry JAMB 1983 Q23 ✓ Answer: E

Which of the following happens during the electrolysis of molten sodium chloride?

A

Sodium ion loses an electron

B

Chlorine atom gains an electron

C

Chloride ion gains an electron

D

Sodium ion is oxidized

E

Chloride ion is oxidized.

Chemistry JAMB 1983 Q24 ✓ Answer: D

Crude petroleum pollutant usually seen on some Nigeria creeks and waterways can be dispersed or removed by.

A

heating the affected parts order to boil off the petroleum

B

mechanically stirring to dissolve the petroleum in water

C

pouring organic solvents to dissolve the petroleum

D

spraying the water with detergents

E

cooling to freeze out the petroleum.

Chemistry JAMB 1983 Q25 ✓ Answer: D

An element is electronegative if

A

it has a tendency to exist in the gaseous form

B

its ions dissolve readily in water

C

it has a tendency to lose electrons

D

it has a tendency to gain electrons

E

it readily forms covalent bonds

Chemistry JAMB 1983 Q26 ✓ Answer: E

Solution X,Y, and Z have pH values 3.0, 5.0 and 9.0 respectively. Which of the following statements is correct?

A

All the solution are acidic

B

All solution are basic

C

Y and Z are more acidic than water

D

Y is more acidic than X.

E

Z is the least acidic

Chemistry JAMB 1983 Q27 ✓ Answer: C

In the reactions (1) H2 (g) + 1 2 O2(g) H 2O(1); H =-2.86kJ (11) C(s) + O2(g) CO2(g); H= -406 kJ the equations imply that [PAGE 4]

A

more heat is absorbed heat is evolved in (1)

B

more heat is absorbed in (11)

C

less heat is evolved in (1)

D

reaction (11) proceeds faster than (1)

E

reaction (1) proceeds faster than (11)

Chemistry JAMB 1983 Q28 ✓ Answer: C

Which of these metals, Mg, Fe, Pb, and Cu will dissolve in dilute HCI?

A

All the metals

B

Mgm Fe, and Cu

C

Mg, Fem and Pb

D

Mg and Fe only

E

Mg only

Chemistry JAMB 1983 Q29 ✓ Answer: B

Stainless steel is an alloy of

A

Carbon, iron and lead

B

Carbon, ion and chromium

C

Carbon iron and copper

D

Carbon, iron and silver

E

Carbon and iron only

Chemistry JAMB 1983 Q30 ✓ Answer: A

What volume of 0.50 MH2SO4 will exactly neutralize 20cm3 of 0.1 M NaOH solution?

A

2.0 cm3

B

5.0 cm3

C

6.8 cm3

D

8.3 cm3

E

10.4 cm3

Chemistry JAMB 1983 Q31 ✓ Answer: B

Which of the following pair of gases will NOT react further with oxygen at a temperature between 30oC and 400oC?

A

SO2 and NH3

B

CO2 and H2

C

NO2 and SO3

D

SO3 and NO

E

CO and H2

Chemistry JAMB 1983 Q32 ✓ Answer: E

Some metals are extracted from their ores after some preliminary treatments by electrolysis (L) some by thermal reaction(T) and some by a combination of both processes(TL). Which set-up in the following for the extraction of iron copper and aluminum is correct?

A

Iron (L), copper (L) m aluminum (T)

B

Iron (T), copper (L), aluminum (T)

C

Ion (TL), copper (TL), aluminium (TL)

D

Iron (L), copper (T), aluminium (T).

E

Ion (T), copper (L), aluminium (TL).

Chemistry JAMB 1983 Q33 ✓ Answer: A

In the preparation of some pure crystals of Cu (NO3)2 starting with CuO, a student gave the following statements as steps he employed. Which of these shows a flaw in his report?

A

Some CuO was reacted with excess dilute H2SO4

B

The solution was concentrated

C

When the concentrate was cooled, crystals formed were removed by filtration.

D

The crystals were washed with very cold water

E

The crystals were then allowed to dry.

Chemistry JAMB 1983 Q34 ✓ Answer: C

Which of the following seperation processes is most likely to yield high quality ethanol (>95%) from palm wine?

A

Fractional disllation without a dehydrant

B

Simple distillation without a dehydrant

C

Fractional distillation with a dehydrant

D

Column chromatography

E

Evaporation

Chemistry JAMB 1983 Q35 ✓ Answer: D

Increasing the pressure of a gas

A

lowers the average kinetic energy of the molecules

B

decreases the density of the gas

C

decreases the temperature of the gas

D

increases the density of the gas

E

increases the volume of the gas.

Chemistry JAMB 1983 Q37 ✓ Answer: C

3.06 g of a sample of potassium trioxochlorate (v) (KCIO3) was required to make a saturated solution with 10cm3 of water at 25oC. The solubility of the salt at 25oC is [K =39, CI =35.5, O=16]

A

5.0 moles dm3

B

3.0 moles dm3

C

2,5 moles dm3

D

1.0 moles dm3

E

0.5 moles dm3

Chemistry JAMB 1983 Q38 ✓ Answer: C

The cracking process is very important in the petroleum industry because it

A

gives purer products

B

Yields more lubricants

C

Yields more engine fuels

D

Yields more asphalt

E

Yield more candle wax

Chemistry JAMB 1983 Q40 ✓ Answer: E

Which if the following solution will give a white precipitate with barium chloride solution and a green flame test?

A

Na2SO4

B

CuSO4

C

CaSO4

D

CaCI2

E

(NH4)2 SO4

Chemistry JAMB 1983 Q41 ✓ Answer: D

The mass of an atom is determined by

A

its ionization potential

B

its electrochemical potential

C

the number of protons

D

the number of neutrons and protons

E

the number of neutrons and electrons

Chemistry JAMB 1983 Q42 ✓ Answer: E

Which of the following is neutralization reaction?

A

Addition of chloride solution

B

Addition of trioxonirate (V) acid (nitric acid) to distilled water.

C

Addition of trioxonirate (V) acid (nitric acid) to tetraoxosulphate (V1) acid (sulphuric acid). [PAGE 5]

D

Addition of trioxonirate (V) (potassium nitrate) solution

E

Addition of trioxonirate (V) acid (nitric acid) potassium hydroxide solution.

Chemistry JAMB 1983 Q45 ✓ Answer: B

Which of the following statements is FALSE?

A

copper (11) ion can be reduced to copper (1) ion by hydrochloric acid and zinc.

B

Sodium metal dissolves in water giving oxygen

C

Nitrogen is insoluble in water

D

Carbondioxide is soluble in water

E

Lead has a higher atomic weight than copper

Chemistry JAMB 1983 Q46 ✓ Answer: B

When sodium dioxonitrate (111) (HaNO2 \) dissolves is

A

Exothermic

B

Endothermic

C

Isothermic

D

Isomeric

E

Hydroscopic

Chemistry JAMB 1983 Q48 ✓ Answer: A

Zn + H2SO4 ZnCI2 + H2 The rate of the above reaction will be greatly increased if.

A

the zinc is in the powered form

B

a greater volume of the acid is used

C

a smaller volume of the acid is used

D

the reaction vessel is immersed in an ice-bath

E

the zinc is in the form of pellets.

Chemistry JAMB 1983 Q49 ✓ Answer: D

Zn + H2SO4 ZnSO4 + H4 In the above reaction how much zinc will be left undissolve if 2.00 g of zinc treated with 10cm3 of 1.0 M of H2SO4? [Zn =65, S=32, O = 16, H = 1]

A

1.35 g

B

1.00 g

C

0.70 g

D

0.65 g

E

0.06 g

Chemistry JAMB 1983 Q50 ✓ Answer: C

30cm3 of 0.1 M AI(NO3)3 solution is reacted with 100cm3 of 0.15M of NaOH solution. Which is in excess and by how much?

A

NaOH solution, by 70cm3

B

NaOH solution, by 60cm3

C

NaOH solution by 40cm3

D

AI (NO3)3, solution by 20cm3

E

AI (NO3)3 solution, by 10cm3 Chemistry 1984

JAMB Chemistry 1983 past questions