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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 571

waec 2016

Which of the following compounds is/are secondary alkanols?

i) CH₃CH(CH₃)CH₃OH
ii) CH₃CH₂CH(OH)CH₃
iii) CH₃C(OH)(CH₃)CH₃

AI only

BII only

CI and III only

DII and III only

View Explanation & Discuss

Question 572

waec 2016

The compound that makes palm wine taste sour after exposure to the air for few days is

AEthanol

BEthanoic acid

CMethanol

DMethanoic acid

View Explanation & Discuss

Question 573

waec 2016

Ripening of fruits is hastened by using

AEthanol

BEthane

CEthene

DEthyne

View Explanation & Discuss

Question 574

waec 2016

When a compound X is heated with concentrated tetraoxosulphate(VI)acid, it produces an alkene. X is an

AAlkane

BAlkanol

CAlkanoate

DAlkyne

View Explanation & Discuss

Question 575

waec 2016

Amino acids are obtained from proteins by

AHydrolysis

BOxidation

CPolymerization

DReduction

View Explanation & Discuss

Question 576

waec 2016

Consider the following half-cell reactions.
Al_(s) \(\to\) Al³⁺_(aq) + 3e^-
Cu²⁺_(aq) + 2e^- \(\to\) Cu_(s)

The overall equation for the reaction is

AAl_(s) + Cu²⁺_(aq) \(\to\) Al³⁺_(aq) + Cu_(s)

B2Al_(s) + Cu²⁺_(aq) \(\to\) 2Al_(aq) + Cu_(s)

C2Al_(s) + 3Cu²⁺_(aq) \(\to\) 3Cu_(s) + 2Al³⁺_(aq)

D3Al_(s) + 2Cu²⁺_(aq) \(\to\) Cu_(s) + 3Al³⁺_(aq)

View Explanation & Discuss

Question 577

waec 2016

Consider the following ionic equation:
Cr\(_2\)O\(_7\)\(^{2-}\) + 14H\(^+\) + ne- → 2Cr\(^{3+}\) + 7H\(_2\)O.
The value of n in the equation is_______?

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Question 578

waec 2016

The oxidation number of sulphur is +4 in

ANa₂S>₂O₃

BH₂SO₃

CH₂SO₄

DSO₃

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Question 579

waec 2016

Which of the following substances is a non-electrolyte?

AH₂SO₄

BCH₃COOH

CC₆H₁₂O₆

DNH₄Cl

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Question 580

waec 2016

Chlorine water is used as a bleaching agent because it is

AAn acidic solution

BAn alkaline solution

CAn oxidizing agent

DA reducing agent

View Explanation & Discuss

Question 581

waec 2016

The quality of electricity required to discharge 1 mole of univalent ion is

A9600C

B48250C

C96500C

D193000C

View Explanation & Discuss

Question 582

waec 2016

A compound with molecular formula CH₂O₂ is

AA Carbohydrate

BA Carboxylic acid

CAn alkanol

DAn ester

View Explanation & Discuss

Question 583

waec 2016

Which of the following bonds are broken when ethanol is boiled?

I. Covalent bonds
II. Ionic bonds
III. Hydrogen bonds

AI only

BII only

CIII only

DI, II, III

View Explanation & Discuss

Question 584

waec 2016

Which of the following salts when dissolved in water will form a solution that will change blue litmus to red?

ACH₃COONa

BNH₄Cl

CNaCl

DKCl

View Explanation & Discuss

Question 585

waec 2016

On evaporation to dryness, 350cm\(^3\) of saturated solution of salt Z gave 55.5g of salt. What is the solubility of the salt? [Z = 101]

A1.57 moldm^-3

B3.14 moldm^-3

C6.28 moldm^-3

D12.56 moldm^-3

View Explanation & Discuss

Question 586

waec 2016

Which of the following factors will affect the rate of the reaction represented by the following equation?
2HCl(aq) + CaCO3(s) \(\rightarrow\) CaCl2(aq) + H2O(1) + CO2(g)

I. Pressure
II.Concentration
III. Nature of reactants
IV. Temperature

AI and II only

BII, III and IV only

CI, II and III only

DI, II. III and IV

View Explanation & Discuss

Question 587

waec 2016

Chemical equilibrium is attained when

AAll the reactants have been completely used up

BThe reaction goes to completion

CThe concentration of reactants and products remain constant

DThe concentration of reactants and products are equal

View Explanation & Discuss

Question 588

waec 2016

The refreshing characteristic taste of fizzy drinks is due ot the presence of

ACarbon(IV)oxide

BGlucose

CHydrogen

DSodium Citrate

View Explanation & Discuss

Question 589

waec 2016

Consider the following reaction equation
H₃O⁺_(aq) + OH_(aq) \(\rightarrow\) 2H₂O₍₁₎
The reaction represents

AEsterification

BHydrolysis

CNeutralization

DRedox

View Explanation & Discuss

Question 590

waec 2016

The pH of four solutions M,N,Q and R are 2,6,8 and 11 respectively.
Which of the following deductions about the solutions is correct?

AThe pH of N is increased when the solution is diluted

BThe pH of Q is increased when the solution is evaporated

CM is the most alkaline solution

DR is the most acidic solution

View Explanation & Discuss

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