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Chemistry Past Questions

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2,505 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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Past Questions

2,505 questions

Question 1 of 20 2,505 total questions

Question 1171

jamb 1981

Which of the following is the electronic configuration of sodium?
(Atomic number of Na = 11)

A1s² 2s²2p⁶ 3s²

B1s² 2s²2p⁶ 3s² 3p1s² 2s²2p⁶ 3s¹

C1s² 2s²2p⁶ 3s¹

D1s² 2s²2p⁶ 3s^°

E1s² 2s²2p⁶ 4s¹

View Explanation & Discuss

Question 1172

jamb 1981

A polymerization reaction is one in which?

Asmall molecules form giant molecules

Batoms form molecules

Cgiant molecules form small molecules

Dmolecules form volatile compounds

Ea molecule rearranges itself

View Explanation & Discuss

Question 1173

jamb 1981

Allotropes are elements having?

Adifferent physical but the same chemical properties

Bdifferent chemical but the same physical properties

Cthe same chemical and physical properties

Ddifferent atomic structure

Ethe same position in the periodic table

View Explanation & Discuss

Question 1174

jamb 1981

Which of the following can have an isomer?

AC₂H₄

BC₄H₁₀

CC₃H₈

DC₂H₆

EC₆H₆

View Explanation & Discuss

Question 1175

jamb 1981

In the preparation of ammonia, which of the following is used as the drying agent?

ACaO

BCaCI₂

CConc. H₂SO₄

DP₂O₅

EH₃PO₄

View Explanation & Discuss

Question 1176

jamb 1981

Which of the following processes takes place during electrolysis?

APositive ions are discharged at the anode bby gaining sufficient electrons to become neutral

BNegative ions are dicharged at the anode by gaining suficient electrons to become neutral

CPositive ions are discharged at the anode by losing sufficient electrons to become neutral

DNegative ions are discharge at the anode by losing sufficient electrons to become neutral

ENothing happens

View Explanation & Discuss

Question 1177

jamb 1981

The brown coloration in nitric acid prepared in the laboratory can be removed by?

Aheating the acid

Bbubbling air through the acid

Ccooling the acid

Dadding a decolorizing agent

Eadding a base

View Explanation & Discuss

Question 1178

jamb 1981

In the reaction
C + 2HNO₃ → CO₂ + NO₂ + NO + H₂O nitric acid is acting as?

Aa reducing agent

Ba nitrating agent

Can oxidizing agent

Da catalytic agent

Ea neutralizing agent

View Explanation & Discuss

Question 1179

jamb 1981

If concentrated sulphric acid is added to sugar and warmed gently, the sugar changes from white to brown and finally to a black mas of carbon. In this reaction, concentrated sulphuric acid is acting as ?

Aa drying agent

Ban oxidizing agent

Ca dehydrated agent

Da reducing agent

Ea hydrolysing agent

View Explanation & Discuss

Question 1180

jamb 1981

Which of the following statements is NOT true of electrovalent compounds?

AThey are solids

BThey do not vaporized easily

CThey usually dissolve in water

DThe elements forming the compounds normally have their valency electrons in a shared state

EThey conduct electricity

View Explanation & Discuss

Question 1181

jamb 1981

the number of atoms in one mole of a substance is equal to?

Athe atomic number

Bthe avogadro number

Cthe gas constant

Dthe number of neutrons

Ethe number of electrons

View Explanation & Discuss

Question 1182

jamb 1981

Oxidation is the process of?

Again of electrons

Bloss of electrons

Cgain of hydrogen

Dloss of oxygen

Eaddition of an electropositive element to a substance

View Explanation & Discuss

Question 1183

jamb 1981

Sodium and potassium belong to the same group of the Periodic Table. This is because?

Aboth are metals

Bboth are soft and lighter than water

Cboth form cations by losing electrons

Dboth have identical electronic configuration

Eboth react with water vigorously

View Explanation & Discuss

Question 1184

jamb 1981

The mass number of an atom is?

Athe number of electrons in the atom

Bthe number of protons in the nucleus of the atom

Cthe number of neutrons in the nucleus of the atom

Dthe sum of numbers of electrons and protons inthe atom

Ethe sum of numbers of proton and neutrons in the nucleus of the atom

View Explanation & Discuss

Question 1185

jamb 1981

For iron to rust, there should be present?

Aoxygen

Bmoisture

Ccarbondioxide

Doxygen and moisture

Eoxygen, moisture and carbondioxide

View Explanation & Discuss

Question 1186

jamb 1981

Methane is member of the homologous series called?

Aalkenes

Balcohols

Cesters

Dalkanes

Ealkynes

View Explanation & Discuss

Question 1187

jamb 1981

The oxidation number of manganese in KMnO₄ is?

A+1

B+3

C+5

D+7

E+2

View Explanation & Discuss

Question 1188

jamb 1981

An example of a strong electrolyte is?

Aethyl acetate

Bethanol

Cglucose

Dsodium formate

Eformic acid

View Explanation & Discuss

Question 1189

jamb 1981

When glowing splint is inserted into the mouth of a jar containing a gas, the splint is extinguished. The gas gives a white precipitate when passing into barium hydroxide. The gas is?

Amethane

Bhydrogen chloride

Chydrogen

Dnitrogen

Ecarbondioxide

View Explanation & Discuss

Question 1190

jamb 1981

When a bottle of Coca-Cola is opened, bubbles of evolve. The gas is?

Ahydrogen

Bcarbon monoxide

Ccarbon dioxide

Dsulphur oxide

Echlorine

View Explanation & Discuss

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