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Chemistry Past Questions

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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 1931

jamb 1987

Inspite of the electronic configuration, 1s²2s²2p², carbon is tetraavalent because?

Athe electrons in both 2s and 2p orbitals have equal energy

Bthe electrons in both 2s and 2p orbitals are equivalent

Cboth the 2s and 2p orbitals hybridizes

Dthe six orbitals hybridize to four

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Question 1932

jamb 1987

Corrosion is exhibited by?

Airon only

Belectropostive metals

Cmetals below hydrogen inthe electrochemical series

Dall metals

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Question 1933

jamb 1987

Alloys are best prepared by?

Ahigh temperature weilding of the metals

Belectrolysis using the major metallic component as cathode

Creducing a mixture of the oxies of the elements

Dcooling a molten mixture of the necessary elements

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Question 1934

jamb 1987

Stainless steel is an alloy of?

AIron, carbon and silver

Biron, carbon and lead

Ciron, carbon and chromium

Diron and carbon only

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Question 1935

jamb 1987

Which of the following elements will form oxide which will dissolve both in dilute HNO₃ and NaOH solutions to form salts?

AAl

BMg

CAg

DMn

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Question 1936

jamb 1987

When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?

Abubbling it through concentrated H₂SO₂

Bbubbling it through water and then passing it through calcium oxide

Cpassing it directly through calcium oxide

Dpassing it directly through calcium chloride

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Question 1937

jamb 1987

Which of the following gases can best be used for demonstrating the fountain experiment?
i) Nitrogen (ii) Ammonia (iii) Nitrogen (I) oxide
(iv) Hydrogen chloride.

Aii and iii

Bi and iii

Cii and iv

Dii only

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Question 1938

jamb 1987

In which of the following pairs of element is allotropy exhibited by each element?

APhosphorus and hydrogen

BOxygen and chlorine

CSulphur and nitrogen

DOxygen and sulphur

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Question 1939

jamb 1987

The best treatment for a student who accidentally poured concentrated tetraoxosulphate (VI) acid on his skin in the laboratory is to wash the skin with?

Acold water

Bsodium hydroxide solution

Ciodine solution

Dsodium trioxocarbonate (IV) solution

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Question 1940

jamb 1987

Magnesium ribbon was allowed to burn inside a given gas P leaving a white solid residue Q. Addition of water to Q liberated a gas which produced dense white fumes with a drop of hydrochloric acid. The gas P was?

Anitrogen

Bchlorine

Coxygen

Dsulphur (IV) oxide

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Question 1941

jamb 1987

The reaction between sulphur (IV) oxide and oxygen is represented by the equilibrium reaction 2SO_2(g) + O_2(g) ↔ 2SO_3(g), ∆H = -196 kJ. What factor would influence increased production of SO_3(g)?

AAddition of a suitable catalyst

BIncrease in the temperature of the reaction

CDecrease in the temperature of the reaction

DDecrease in the concentration of SO_2(g)

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Question 1942

jamb 1986

When 50cm³ of a saturated solution of sugar (molar mass 342.0g) at 40^oC was evaporated to dryness, 34.2g of dry solid was obtained. The solubility of sugar at 40^oC is

A10.0 moles dm^-3

B7.0 moles dm^-3

C3.5 moles dm^-3

D2.0 moles dm^-3

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Question 1943

jamb 1986

Which of the following groups of physical properties increases from left to right of the periodic table?

i. Ionization energy ii. Atomic radius iii. Electronegativity iv. Electron affinity

Ai and ii

Bi, ii and iii

Ciii and iv

Di, iii and iv

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Question 1944

jamb 1986

An element with atomic number twelve is likely to be

Aelectrovalent with a velocity of 1

Belectrovalent with a valency of 2

Ccovalent with a valency of 2

Dcovalent with valency of 4

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Question 1945

jamb 1986

The relationship between the velocity (U) of gas molecules and their relative molecular mass (M) is shown by the equation

AU = (kM)\(\frac{1}{2}\)

BU = (kM)²

CU = \(\sqrt{\frac{k}{m}}\)

DU = \(\frac{k}{m}\)

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Question 1946

jamb 1986

How much of magnesium is required to react with 260cm3 of 0.5 M HCl? [Mg = 24]

A0.3g

B1.5g

C2.4g

D3.0g

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Question 1947

jamb 1986

The number of atoms of chlorine present in 5.85g of NaCl is [Avogadro's Number = 6.02 x 10\(^{23}\)]

A6.02 x 10²²

B5.85 x 10²³

C6.02 x 10²³

D5.85 x 10²⁴

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Question 1948

jamb 1986

10cm³ of hydrogen fluoride gas react with 5cm³ of dinitrogen difluoride gas (N²F₂) to form 10₃ of a single gas. Which of the following is the most likely equation of the reaction?

AHF + N₂F₂ \(\to\) N₂HF₃

B2HF + N₂F₂ \(\to\) 2NHF₂

C2HF + N₂F₂ \(\to\) N₂H₂F₃

DHF + 2N₂F₂ \(\to\) N₄HF₂

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Question 1949

jamb 1986

Use the options above to answer this question. Which is the structural formula for pent-2-enoic acid?

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Question 1950

jamb 1986

The tabulated results below were obtained by titration 10.0 cm₃ of water with soup. The titration was repeated with the same sample of water after boiling. The ratio of permanent to temporary hardness is

A1.5

B1.4

C4.1

D5.1

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