2008 NECO Chemistry Past Questions & Answers

Question 1

The electrode potential in volts of 2H$^+$(aq) / H$_2$(q) system is

Accepted Answer

E. $ 0 $

Answer

A. -2.87

Answer

B. -2.71

Answer

C. 0.8

Answer

D. 1.68

Question 2

A substance is said to be hygroscopic when it

Accepted Answer

B. absorbs atmospheric moisture but does not go into solution

Answer

A. absorbs atmospheric moisture and then goes into solution

Answer

C. changes colour

Answer

D. is not affected by atmospheric moisture

Answer

E. losses its water of crystallization

Question 3

The action of zinc on an acid produces

Accepted Answer

B. hydrogen

Answer

A. chlorine

Answer

C. nitrogen

Answer

D. sulphur

Answer

E. water vapour.

Question 4

During the electrolysis of sodium Chloride solution, hydrogen is discharged at the carbon cathode because

Accepted Answer

C. hydrogen is lower than sodium in the electrochemical series.

Answer

A. hydrogen ions are in greater concentration than sodium ions.

Answer

B. hydrogen is higher than sodium in the electrochemical series.

Answer

D. of the nature of the electrodes.

Answer

E. the concentration of sodium ions is greater than that of the hydrogen ion in the electrolyte.

Question 5

The high boiling point of hydrogen fluoride can be explained in terms of?

Accepted Answer

E. hydrogen bonds.

Answer

A. covalent bonds.

Answer

B. dative bonds.

Answer

C. dipole-dipole bonds

Answer

D. electrovalent (ionic) bonds.

Question 6

A measure of the degree of disorderliness in a chemical system is known as the

Accepted Answer

C. entropy

Answer

A. activation energy

Answer

B. enthalpy

Answer

D. equilibrium

Answer

E. free energy.

Question 7

The planet with the highest number of moon is

Accepted Answer

B. Jupiter

Answer

A. Earth

Answer

C. Uranus

Answer

D. Pluto

Answer

E. Venus.

Question 8

If two elements X and Z with electronic configurations 2,8.3 and2,8,6 respectively combine, the compound formed will have the formula

Accepted Answer

D. X2Z3

Answer

A. XZ

Answer

B. XZ2

Answer

C. X2Z

Answer

E. X3Z2

Question 9

An element Z has a combining power of 3. Which of the following formulae is correct of its compound?

Accepted Answer

D. Z203

Answer

A. ZS3

Answer

B. ZSO3

Answer

C. ZS04

Answer

E. Z3Cl2

Question 10

What is the maximum number of electrons that an f-orbital can accommodate?

Accepted Answer

E. 14

Answer

A. 2

Answer

B. 6

Answer

C. 7

Answer

D. 10

Question 11

Chlorine atom forms Cl- by

Accepted Answer

B. gaining an electron

Answer

A. donating lone pair of electrons

Answer

C. losing an electron

Answer

D. sharing an electron

Answer

E. sharing a lone pair of electrons.

Question 12

The following gases are diatomic EXCEPT

Accepted Answer

B. Helium

Answer

A. Fluorine

Answer

C. Hydrogen

Answer

D. Nitrogen

Answer

E. Oxygen

Question 13

$ ^{234}_{90}Th → ^{234}_{91}Pa + X $ In the nuclear reaction above, X is

Accepted Answer

B. $ ^0_{-1}e $

Answer

A. $ ^0_1e $

Answer

C. $ ^4_2He $

Answer

D. $ ^1_0n $

Answer

E. $ ^1_1p$

Question 14

A device used in the laboratory for intermittent production of gases without heating is

Accepted Answer

D. kipp’s apparatus

Answer

A. aspirator

Answer

B. delivery tube

Answer

C. fume cupboard

Answer

E. muller counter

Question 15

Chromatography is used to separate components of mixtures which differ in their rates of

Accepted Answer

B. migration

Answer

A. diffusion

Answer

C. reaction

Answer

D. sedimentation

Answer

E. sublimation.

Question 16

Which of the following will Increase the rate of reaction of Chips of a metal M as shown in the equation below? M(s)+2HC1(aq) → MCI2 (aq) + H2(g)

Accepted Answer

D. Grinding the metal into powder

Answer

A. Adding some distilled water

Answer

B. Decreasing the temperature

Answer

C. Diluting the hydrochloric acid

Answer

E. Increasing the pressure

Question 17

When sodium hydroxide solution is added to a solution of zinc salt, the white precipitate formed re-dissolve in excess sodium hydroxide because

Accepted Answer

D. zinc hydroxide is amphoteric

Answer

A. sodium hydroxide is a strong alkali

Answer

B. sodium is more reactive than zinc

Answer

C. zinc is more reactive than sodium

Answer

E. zinc hydroxide is unstable

Question 18

The most efficient absorber of ultraviolet radiation in the atmosphere is

Accepted Answer

E. O3

Answer

A. CO2

Answer

B. H2

Answer

C. H2O

Answer

D. 02

Question 19

Which of these arrangement of elements is in order of increasing ionization energy?

Accepted Answer

B. Boron, Carbon, Nitrogen, Flourine

Answer

A. Boron, Carbon, Flourine, Nitrogen

Answer

C. Carbon, Boron, Nitrogen, Flourine

Answer

D. Flourine, Nitro9en, Carbon, Boron

Answer

E. Nitrogen, Flourine, Carbon, Boron

Question 20

Bauxite is the ore of

Accepted Answer

A. aluminium

Answer

B. calcium

Answer

C. Iron

Answer

D. sodium

Answer

E. magnesium

Question 21

The molecular formula of ethylbutanoate is?

Accepted Answer

E. C3H7COOC2H5

Answer

A. CH5COOC26

Answer

B. C3HCOOC2H7

Answer

C. C3H7COOC3H7

Answer

D. C3H7COOC4H9

Question 22

In which of the following equations can Le-chartelier’s principle be applied?

Accepted Answer

C. N2(g) +3H2(g) 
⇌ 2NH3(g)

Answer

A. H2(g)+S(g) → H2(g)

Answer

B. 2H2S(g) + O2 (g) → 2H2O(l) + 2SO2(g)

Answer

D. NaOH(aq) +CO2(g) → Na2CO3(aq) + H2O(l)

Answer

E. S(s) + 02(g) → SO2(g)

Question 23

What type of bond holds hydrogen fluoride molecules together when forming larger aggregate?

Accepted Answer

C. Hydrogen

Answer

A. Covalent

Answer

B. Dative

Answer

D. Ionic

Answer

E. Metallic

Question 24

Which of these is NOT a physical property f water?

Accepted Answer

E. is neutral to litmus

Answer

A. Can be used to dissolve organic substances

Answer

B. Has a boiling point of 100 ° C

Answer

C. Has a density of 19cm3 at 40 °C

Answer

D. Has a freezing point of 0 ° C

Question 25

The gas in air used by plants for photosynthesis is

Accepted Answer

B. Carbon (IV) oxide

Answer

A. Argon

Answer

C. Nitrogen

Answer

D. Oxygen

Answer

E. Water vapour.

Question 26

The reaction of hydrochloric acid and calcium trioxocarbonate (IV) produces

Accepted Answer

A. calcium chloride, carbon (IV) oxide and water

Answer

B. calcium chloride, and trioxocarbonate (IV) acid

Answer

C. calcium hydroxide, carbon (IV) oxide and chlorine gas

Answer

D. calcium hydroxide, carbon (IV) oxide and water

Answer

E. calcium metal and water.

Question 27

Pipe-borne water is usually chlorinated in order to

Accepted Answer

C. kill harmful bacteria in the water

Answer

A. coagulate sediments in the water

Answer

B. improve taste of the water

Answer

D. make it pure

Answer

E. remove the hardness in the water

Question 28

If two metallic ions of the same concentration migrate to a graphite cathode, the one that would be preferentially discharged is that with the

Accepted Answer

D. stronger tendency to accept electrons

Answer

A. greater stability in solution

Answer

B. lower electrical charge

Answer

C. smaller mass

Answer

E. stronger tendency to lose electrons.

Question 29

pH is define as

Accepted Answer

C. –log [H+]

Answer

A. [H+]

Answer

B. –log [H]

Answer

D. log [H]

Answer

E. log [H+]

Question 30

Brownian motion explains

Accepted Answer

D. Molecular motion in liquids and gases

Answer

A. Boyle’s law

Answer

B. Collision theory

Answer

C. Laws of chemical combination

Answer

E. Vibrational motion in liquids.

Question 31

Which of the following is a component of the car exhaust?

Accepted Answer

E. Lead

Answer

A. Aluminium

Answer

B. Calcium

Answer

C. Iron

Answer

D. Zinc

Question 32

Matter is neither created nor destroyed in the course of any chemical reactions is a statement of the law of

Accepted Answer

B. conservation of mass

Answer

A. combining volumes

Answer

C. definite proportion

Answer

D. multiple proportion

Answer

E. reciprocal proportion.

Question 33

The rate of a chemical reaction is NOT affected by one of these factors

Accepted Answer

A. colour

Answer

B. concentration

Answer

C. presence of light

Answer

D. surface area

Answer

E. temperature

Question 34

In which of these groups will all the substances be insoluble in water?

Accepted Answer

E. ZnCO3, BaSO4,AgCl

Answer

A. Na2CO3, KNO3,(NH4)2C03

Answer

B. NaHCO3, PbSO4, CaSO4

Answer

C. K2C03, CaSO4, AgNO3

Answer

D. PbCl2, NaCl, ZnCl2

Question 35

Which of the following compounds is unsaturated?

Accepted Answer

E. 3-methylbut-l-ene

Answer

A. Cyclohexane

Answer

B. Methoxyethane

Answer

C. 1 ,2-dibromoethane

Answer

D. 2,2,3-trimethylpentane

Question 36

The following acids are monobasic EXCEPT

Accepted Answer

B. ethanedioic acid

Answer

A. dioxonitrate (Ill) acid

Answer

C. hydrobromic acid

Answer

D. methanoic acid

Answer

E. oxochlorate (I) acid

Question 37

A solution is prepared by dissolving I .96g of H2SO4 in 250 cm3 of its solution. What is the concentration in moles per dm3?

Accepted Answer

B. 0.08

Answer

A. 0.008

Answer

C. 0.1

Answer

D. 0.8

Answer

E. 8.02

Question 38

What is the colour of phenolphthalein indicator in a basic medium?

Accepted Answer

D. Pink

Answer

A. Blue

Answer

B. Colourless

Answer

C. Orange

Answer

E. Yellow

Question 39

Which of the following laws is obeyed If at constant temperature, 200cm of hydrogen at 1.5 × 10m5Nm-2pressure becomes 300cm3 at 1.0 × 105Nm-2 pressure?

Accepted Answer

B. Boyle’s

Answer

A. Avogadro’s

Answer

C. Charles’

Answer

D. Faraday’s

Answer

E. Graham’s

Question 40

When dust particles collide randomly in a beam of Sunlight, the phenomenon observed is known as

Accepted Answer

A. Brownian movement.

Answer

B. Dialysis

Answer

C. Diffusion

Answer

D. Osmosis

Answer

E. Tyndall effect

Question 41

A chemical system is at equilibrium when

Accepted Answer

B. δ G is zero

Answer

A. δ G is positive

Answer

C. δ S is negative

Answer

D. δ S is positive

Answer

E. δ S is zero.

Question 42

The type of reaction ethyne mainly undergoes is

Accepted Answer

A. addition

Answer

B. carboxylation.

Answer

C. esterification

Answer

D. saponification

Answer

E. substitution

2008 NECO Chemistry Past Questions

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