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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

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Question 1551

jamb 1997

\(\frac{1}{2}\)N\(_2\)(g) + \(\frac{1}{2}\)O\(_2\)(g) → NO(g) ∆H° = 89 KJ mol\(^{-1}\). If the entropy change for the reaction above at 25°C is 11.8 J mol\(^{-1}\), calculate the change in free energy. ∆G°, for the reaction at 25°C?

A88.71 KJ

B85.48 KJ

C-204.00 KJ

D-3427.40 KJ

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Question 1552

jamb 1997

25 cm\(^3\) of 0.02 M KOH neutralized 0.03 g of a monobasic organic acid having the general formula C\(_n\)H\(_{2n + 1}\)COOH. The molecular formula of the acid is?

(C = 12, H = 1, O = 16)

AHCOOH

BC₂H₅COOH

CCH₃COOH

DC₃H₇COOH

View Explanation & Discuss

Question 1553

jamb 1997

The synthetic detergents are preferred to soap for laundry using hard water because?

Adetergents are water soluble while soap is not

Bthe calcium salts of detergents are water soluble

Cthe magnesium salt of soap is soluble in hard water

Dsoap does not have a hydrocarbon terminal chain

View Explanation & Discuss

Question 1554

jamb 1997

Synthetic rubber obtained by the polymerization of chlorobutadiene in the presence of sodium is called?

Ateflon

Bisoprene

Cpolythene

Dneoprene

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Question 1555

jamb 1997

The final product of the reaction of ethyne with hydrogen iodide is?

ACH₃—CHI₂

BCH₂l—CH₂I

CCH₃—CI₃

DCH₂ = CHI

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Question 1556

jamb 1997

The reaction of an alkanol with an alkanoic acid in the presence of concentrated H₂SO₄ will produce an?

Aalkanal

Balkanoate

Calkanone

Dalkyne

View Explanation & Discuss

Question 1557

jamb 1997

An undesirable paraffin in the petroleum industry which is particularly prone to knocking is?

Aiso-octane

Bn-heptane

Ciso-heptane

Dn-octane

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Question 1558

jamb 1997

A sample of a substance containing only C and H burns in excess O₂ to yield 4.4g of CO₂
and 2.7 g of H₂O. The empirical formula of a substance is?

(C = 12, O = 16, H = 1)

ACH₃

BCH₂

CCH₄

DC₂H₂₄

View Explanation & Discuss

Question 1559

jamb 1997

Sodium hydroxide is prepared commercially from sodium chloride solution by?

Aelectrolysis using mercury as cathode

Bhydrolysis in steam using a catalyst

Celectrolysis using iron as anode

Dtreating sodium chloride with ammonia and carbon (IV) oxide

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Question 1560

jamb 1997

Which of the additives could improve the quality of steel?

ASilicon

BSulphur and phosphorus

CCarbon

DChromium and nickel

View Explanation & Discuss

Question 1561

jamb 1997

The removal of rust from iron by treatment with tetraoxosulphate (IV) acid is based on the?

Ahydrolysis of the iron

Breaction of acid with base

Coxidationof the rust

Ddehydration of the iron

View Explanation & Discuss

Question 1562

jamb 1997

2X_(aq) + MnO_2(s) + 4H⁺_(aq) → X_2(g) + Mn²⁺_(aq) + 2H₂O.
The reaction above can be used for the laboratory preparation of all halogens except fluorine because it is?

Aa poisionous gas

Ban oxidizing agent

Celectronegative in nature

Dhighly reactive

View Explanation & Discuss

Question 1563

jamb 1997

Coal gas is made up of carbon (II) oxide, hydrogen and?

Anitrogen

Bair

Cargon

Dmethane

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Question 1564

jamb 1997

A compound that will NOT produce oxygen on heating is?

Apotasium dioxonitrate (III)

Blead (IV) oxide

Cpotassium trioxochlorate (V)

Dpotassium trioxonitrate (V)

View Explanation & Discuss

Question 1565

jamb 1997

mE + nF → pG + qH. In the equation above, the equilibrium constant is given by?

A(E)^m(F)ⁿ/ (G)ⁿ(H)^q

B(E)(F) / (G)(H)

C(G)^p(H)^q / (E)^m(F)ⁿ

D(G)(H) / (E)(F)

View Explanation & Discuss

Question 1566

jamb 1997

Oxidation of concentrated hydrochloric acid with manganese (IV) oxide liberates a gas used in the?

Amanufacture of tooth pastes

Btreatment of simple golitre

Cvulcanization of rubber

Dsterilization of water

View Explanation & Discuss

Question 1567

jamb 1997

One method of driving the position of equilibrium of an endothermic reaction forward is to?

Aincrease temperature at constant pressure

Bdcrease pressure at constant temperature

Ccool down the apparatus with water

Ddecreases temperature at constant pressure

View Explanation & Discuss

Question 1568

jamb 1997

If the rate law obtained for a given reaction is rate = k(X)ⁿ (Y)^m, what is the overall order of the reaction?

Anm

Bn/m

Cn + m

Dn - m

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Question 1569

jamb 1997

2SO2(g) + O2(g) → 2SO3. In the reaction above, the standard heats of formation of SO2(g) and SO3(g) are -297 KJ mol-1 and -396 kJ/mol respectively. The heat change of the reaction is?

A-99 kJ mol^-

B-198 kJ mol^-

C+198 kJ mol^-

D+683kJ mol^-

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Question 1570

jamb 1997

2H₂S_(g) + SO_2(g) + H₂O_(I) → 3S_(s) + 3H₂O_(I)..........(i) 3CuO_(s) + 2NH_3(g) → 3Cu_(s) + 3H₂O_(I) + N_2(g).........(II) In the equations above, the oxidizing agent (I) and the reducing agent in (II) respectively are?

AH₂S_{and NH₃}

BSO₂ and CuO

CSO₂ and NH₃

DH₂S_{and CuO}

View Explanation & Discuss

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