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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 701

jamb 2014

A hydrocarbon has an empirical formula CH and a vapour density of 39. Determine its molecular formula.

[C = 12, H = 1]

AC₂H₆

BC₃H₈

CC₃H₄

DC₆H₆

View Explanation & Discuss

Question 702

jamb 2014

CH3COOC2H5(1) + H2O(1) ⇌ CH 3COOH (aq) + C 2H 5OH (aq)

The purpose of H+ in the reaction above is to

Aincrease the yield of products

Bmaintain the solution at a constant PH

Cincrease the rate of the hydrolysis

Ddecrease the rate of the reverse reaction

View Explanation & Discuss

Question 703

jamb 2014

The polymer used in making car rear lights is

Aperspex

Bbakeelite

Cpolystyrene

Dpolyacrylonitrile

View Explanation & Discuss

Question 704

jamb 2014

The process of converting starch to ethanol is

Acracking

Bdistillation

Cfermentation

Doxidation

View Explanation & Discuss

Question 705

jamb 2014

Due to the unstable nature of ethyne, it is stored by dissolving in

Aethane-1,2-diol

Bpropanol

Cethanoic acid

Dpropanone

View Explanation & Discuss

Question 706

jamb 2014

Ethyne is passed through a hot tube containing organo-nickel catalyst to produce

Aisoprene

Bpolythene

Cethanol

Dbenzene

View Explanation & Discuss

Question 707

jamb 2014

The alkanol obtained from the production of soap is

Apropanol

Bethanol

Cglycerol

Dmethanol

View Explanation & Discuss

Question 708

jamb 2014

The general formula of haloalkanes where X represents the halide is

AC_n H _2n-1X.

BC _nH _2nX.

CC _nH _2n+2 X

DC _nH _2n+1X

View Explanation & Discuss

Question 709

jamb 2014

A few drops of NaOH solution was added to an unknown salt forming a white precipitate which is insoluble in excess solution. The cation likely present is

AZn²⁺

BPb²⁺

CCa²⁺

DAl³⁺

View Explanation & Discuss

Question 710

jamb 2014

A compound that gives a brick-red colour to a non-luminous flame is likely to contain

Acopper ions

Bsodium ions

Ccalcium ions

DPotassium ions

View Explanation & Discuss

Question 711

jamb 2014

In the electrolytic extraction of calcium from calcium chloride, the cathode is

Azinc

Bgraphite

Cplatinum

Diron

View Explanation & Discuss

Question 712

jamb 2014

In the extraction of sodium from fused sodium chloride, the anode is made of platinum because

Asodium is formed at the anode

Bchlorine is formed at the anode

Csodium does not react with platinum

Dchlorine does not react with platinum

View Explanation & Discuss

Question 713

jamb 2014

Fluorine does not occur in the free state in nature because

Ait is a poisonous gas

Bit belongs to the halogen family

Cit is inert

Dof its high reactivity

View Explanation & Discuss

Question 714

jamb 2014

In a chemical reaction, the change in concentration of a reactant with time is

Aentropy of reaction

Benthalpy of reaction

Crate of reaction

Dorder of reaction

View Explanation & Discuss

Question 715

jamb 2014

In an equilibrium reaction, which of the following conditions indicates that maximum yield of the product will be obtained?

AEquilibrium constant is very large

B∆H - T∆S = O

C∆ H > T ∆ S

DEquilibrium constant is less than zero

View Explanation & Discuss

Question 716

jamb 2014

If the change in free energy of a system is -899 Jmol^-1 and the entropy change is 10Jmol^-1k^-1 at 250C, calculate the enthalpy change.

A+2081 Jmol^-1

B-2081 Jmol^-1

C-649 Jmol^-1

D+649 Jmol^-1

View Explanation & Discuss

Question 717

jamb 2014

How many faraday of electricity is required to produce 0.25 mole of copper?

A1.00F

B0.01F

C0.05F

D0.50F

View Explanation & Discuss

Question 718

jamb 2014

Calculate the quantity of electricity in coulombs required to liberate 10g of copper from a copper compound

[Cu=64, F = 96500 Cmol-1]

A32395.5

B30156.3

C60784.5

D15196.5

View Explanation & Discuss

Question 719

jamb 2014

\(H_2O_{(g)} + C_{(s)} → H_{2(g)} + CO_{(g)}\)

The oxidizing agent in the reaction above is

ACO_(g)

BC_(s)

CH₂O_(g)

DH₍₂₎_(g)

View Explanation & Discuss

Question 720

jamb 2014

Zn _(s) + CuSO ₄(aq) → ZnSO ₄(aq) + Cu _(s)
In the reaction above, the oxidation number of the reducing agent changes from

A0 to + 4

B0 to + 2

C+ 1 to + 2

D+ 1 to + 3

View Explanation & Discuss

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