JAMB Chemistry 2010 past questions and answers

Which of the following is an example of a mixture?

1. A.Common salt
2. B.Blood
3. C.Sand
4. D.Washing soda

Calculate the percentage by mass of nitrogen in calcium trioxonitrate (V). [Ca = 40, N = 14, O = 16]

1. A.8.5 %
2. B.13.1 %
3. C.17.1 %
4. D.27.6%

The droplets of water observed around a bottle of milk taken out of the refrigerator is due to the fact that the

1. A.water vapour in the air around the bottle gains some energy from the bottle
2. B.temperature of the milk drops as it loses heat into the surroundings
3. C.saturated vapour pressure of the milk is equal to the atmospheric pressure
4. D.water vapour in the air around the bottle loses some of its energy to the bottle

The volume of a given gas is V cm³ at P mm Hg. What is the new volume of the gas if the pressure is reduced to half at constant temperature?

1. A.4V cm³
2. B.2V cm³
3. C.V/2 cm³
4. D.V cm³

Moving from left to right across a period, the general rise in the first ionization energy can be attributed to the

1. A.decrease in nuclear charge
2. B.increase in nuclear charge
3. C.decrease in screening effect
4. D.increase in screening effect

How many unpaired electron(s) are there in the nitrogen sub-levels?

1. A.3
2. B.2
3. C.1
4. D.0

The stability of the noble gases is due to the fact that they

1. A.have no electron in their outermost shells
2. B.have duplet or octet electron configurations
3. C.belong to group zero of the periodic table
4. D.are volatile in nature

The maximum number of electrons in the L shell of an atom is

1. A.2
2. B.8
3. C.18
4. D.32

Elements in the same period in the periodic table have the same

1. A.number of shells
2. B.atomic number
3. C.chemical properties
4. D.physical properties

²₁D + ³₁T → ⁴₂He + ¹₀n + energy
The reaction above illustrates

1. A.alpha decay
2. B.artificial transmutation
3. C.nuclear fussion
4. D.nuclear fission

A noble gas with a high power of fog penetration used in aerodrome beacons is

1. A.krypton
2. B.argon
3. C.helium
4. D.neon

Permanent hardness of water can be removed by

1. A.filtration
2. B.adding slaked lime
3. C.adding caustic soda
4. D.boiling

Substances employed as drying agents are usually

1. A.amphoteric
2. B.hygroscopic
3. C.efflorescent
4. D.acidic

Calculate the solubility in mol dm⁻³ of 40g of CuSO₄ dissolved in 100g of water at 120°C. [Cu = 64, S = 32, O = 16]

1. A.4.00
2. B.2.50
3. C.0.40
4. D.0.25

Coffee stains can best be removed by

1. A.kerosine
2. B.turpentine
3. C.a solution of borax in water
4. D.ammonia solution

Carbon (II) oxide is considered dangerous if inhaled mainly because it

1. A.can cause injury to the nervous system
2. B.competes with oxygen in the blood
3. C.competes with carbon (IV) oxide in the blood
4. D.can cause lung cancer

The acid that is used to remove rust is

1. A.boric
2. B.hydrochloric
3. C.trioxonitrate (V)
4. D.tetraoxosulphate (VI)

Calculate the volume of 0.5 mol dm⁻³ H₂SO₄ that is neutralized by 25cm³ of 0.1 mol dm⁻³ NaOH.

1. A.5.0 cm³
2. B.2.5 cm³
3. C.0.4 cm³
4. D.0.1 cm³

The colour of methyl orange in alkaline medium is

1. A.yellow
2. B.pink
3. C.orange
4. D.red

Which of the following salts is slightly soluble in water?

1. A.AgCl
2. B.CaSO₄
3. C.Na₂CO₃
4. D.PbCl₂

6AgNO_3(aq) + PH_3(g) + 3H₂O_(l) → 6Ag_(s) + H₃PO_3(aq) + 6HNO_3(aq)
In the reaction above, the reducing agent is

1. A.HNO_3(aq)
2. B.H₂O_(l)
3. C.PH_3(g)
4. D.AgNO_3(aq)

The IUPAC nomenclature of the compound LiAlH₄ is

1. A.lithium tetrahydridoaluminate (III)
2. B.aluminium tetrahydrido lithium
3. C.tetrahydrido lithium aluminate (III)
4. D.lithium aluminium hydride

Iron can be protected from corrosion by coating the surface with

1. A.gold
2. B.silver
3. C.copper
4. D.zinc

What quantity of aluminium is deposited when a current of 10A is passed through a solution of an aluminium salt for 1930s? [Al = 27, F = 96 500 C mol⁻¹]

1. A.0.2 g
2. B.1.8 g
3. C.5.4 g
4. D.14.2 g

In which of the following is the entropy change positive?

1. A.Thermal dissociation of ammonium chloride
2. B.Reaction between an acid and a base
3. C.Addition of concentrated acid to water
4. D.Dissolution of sodium metal in water

If a reaction is exothermic and there is a great disorder, it means that

1. A.the reaction is static
2. B.the reaction is in a state of equilibrium
3. C.there will be a large increase in free energy
4. D.there will be a large decrease in free energy

In the preparation of oxygen by heating KClO₃ in the presence of MnO₂, only moderate heat is needed because the catalyst acts by

1. A.lowering the pressure of the reaction
2. B.increasing the surface area of the reactant
3. C.increasing the rate of the reaction
4. D.lowering the energy barrier of the reaction

The graph above demonstrates the effect of

1. A.surface area on the rate of reaction
2. B.catalyst on the rate of reaction
3. C.pressure on the rate of reaction
4. D.concentration on the rate of reaction

2H_2(g) + O_2(g) ⇌ 2H₂O_(g) ΔH = −ve
What happens to the equilibrium constant of the reaction above if the temperature is increased?

1. A.It is unaffected.
2. B.It becomes zero.
3. C.It decreases.
4. D.It increases.

To a solution of an unknown compound, a little dilute tetraoxosulphate (VI) acid was added with some freshly prepared iron (II) tetraoxosulphate (VI) solution. The brown ring observed after the addition of a stream of concentrated tetraoxosulphate (VI) acid confirmed the presence of

1. A.CO₃²⁻
2. B.Cl⁻
3. C.SO₄²⁻
4. D.NO₃⁻

In the diagram above, the gas produced is

1. A.NO
2. B.NO₂
3. C.N₂O
4. D.N₂O₄

Which of the following is used as a rocket fuel?

1. A.HNO₃
2. B.CH₃COOH
3. C.H₂SO₄
4. D.HCl

In the diagram above, the purpose of the asbestos is to

1. A.absorb impurities
2. B.catalyze the reaction
3. C.solidify the gas
4. D.dry the gas

A constituent common to bronze and solder is

1. A.lead
2. B.silver
3. C.copper
4. D.tin

When iron is exposed to moist air, it gradually rusts. This is due to the formation of

1. A.hydrated iron (III) oxide
2. B.anhydrous iron (III) oxide
3. C.anhydrous iron (II) oxide
4. D.hydrated iron (II) oxide

A compound gives an orange-red colour to a non-luminous flame. This compound is likely to contain

1. A.Na⁺
2. B.Ca²⁺
3. C.Fe³⁺
4. D.Fe²⁺

The residual solids from the fractional distillation of petroleum are used as

1. A.coatings for pipes
2. B.raw materials for the cracking process
3. C.fuel for driving tractors
4. D.fuel for jet engines

CH₃(CH₂)₃CH(C₃H₇)C₂H₅
The IUPAC nomenclature of the compound above is

1. A.4-ethyloctane
2. B.5-ethyloctane
3. C.5-propylheptane
4. D.3-propylheptane

Which of the following is used as fuel in miners' lamp?

1. A.Ethanal.
2. B.Ethyne.
3. C.Ethene.
4. D.Ethane.

Which of the following organic compounds is very soluble in water?

1. A.CH₃COOH
2. B.C₂H₂
3. C.C₂H₄
4. D.CH₃COOC₂H₅

Benzene reacts with hydrogen in the presence of nickel catalyst at 180°C to give

1. A.xylene
2. B.toluene
3. C.cyclopentane
4. D.cyclohexane

Which of the following is used to hasten the ripening of fruits?

1. A.Ethene.
2. B.Ethanol.
3. C.Ethyne.
4. D.Ethane.

The correct order of increasing boiling points of the following compounds C₃H₇OH, C₇H₁₆ and C₄H₁₀ is

1. A.C₃H₇OH → C₄H₁₀ → C₇H₁₆
2. B.C₄H₁₀ → C₇H₁₆ → C₃H₇OH
3. C.C₇H₁₆ → C₃H₇OH → C₄H₁₀
4. D.C₄H₁₀ → C₃H₇OH → C₇H₁₆

One of the major uses of alkanes is

1. A.as domestic and industrial fuels
2. B.in the hydrogenation of oils
3. C.in the textile industries
4. D.in the production of plastics

The haloalkanes used in the dry-cleaning industries are

1. A.trichloromethane and tetrachloromethane
2. B.chloroethene and dichloroethene
3. C.trichoroethene and tetrachloroethene
4. D.chloroethane and dichloroethene

Two hydrocarbons X and Y were treated with bromine water. X decolorised the solution and Y did not. Which class of compound does Y belong?

1. A.Benzene
2. B.Alkynes
3. C.Alkenes
4. D.Alkanes

The compound that is used as an anaesthetic is

1. A.CCl₄
2. B.CHCl₃
3. C.CH₂Cl₂
4. D.CH₃Cl