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Chemistry Past Questions

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1,623 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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1,623 questions

Question 1 of 20 1,623 total questions

Question 371

waec 2010

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

A9,600 C

B48,250 C

C96,500 C

D193,00 C

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Question 372

waec 2010

What is the change in oxidation number of manganes in the reaction represented by the following equation? MnO^-_4(aq) + 8H⁺_(aq) + 5e^- → Mn²⁺_(aq) + 4H₂O_(l)

A+3 to + 2

B+ 4 to + 2

C+ 5 to + 2

D+ 7 to 2

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Question 373

waec 2010

Which of the following statements about the electrolysis of CuSO4(aq) using copper cathode and platinum anode is not correct?

ACopper is deposited at the cathode

BOxygen is liberated at the anode

Cit is used for the purification of copper

DThe solution becomes acidic

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Question 374

waec 2010

Which of the following statements about the cell notation Mg/Mg\(^{2+}\)//Cu\(^{2+}\)/Cu is correct?

Acopper is the anode

BManesium is reduced

CMagnesium is the anode

DThe double line represents the electrodes

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Question 375

waec 2010

The rate of chemical reaction of solids are not affected by

Acatalyst

Bpressure

Cparticle size

Dtemperature

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Question 376

waec 2010

Consider the equilibrium reaction represented by the following equation: 2SO_2(g) + O_2(g) ⇌ 2SO_3(g); ∆H = 395.7 kJmol^-1 Which of the following statements about the equilibrium system is correct?

AAddition of catalyst changes the equailibrium position

BDecrease in pressure increase in temperature SO₃

CDecrease in pressure increases the equilibrium concentration of O₂

DIncrease in temperatur favours the forward reaction

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Question 377

waec 2010

Which of the following factors would not affect the solubility of a gas?

AConcentration

BNature of solvent

CPressure

DTemperature

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Question 378

waec 2010

Which of the following chlorides is insoluble in water?

AAgCI

BKCI

CNH₄CI

DZnCI₂

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Question 379

waec 2010

The following substances are normal salts except

AAI(NO₃)₃

BFeSO₄

CMg(OH)NO₃

DNaCI

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Question 380

waec 2010

Which of the following equimolar solutions would have the highest conductivity?

ANH₄NO_3(aq)

BNaNO_3(aq)

CMg(NO₃)_2(aq)

DAI(NO₃)_3(aq)

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Question 381

waec 2010

Which of the following oxides is basic?

ANO₂

BAI₂O₃

CSO₂

DCaO

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Question 382

waec 2010

The minimum amount of energy required for effective collisions between reacting particles is known as

Aactivation energy

Bbond energy

Ckinetic energy

Dpotential energy

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Question 383

waec 2010

The determination of heat of combustion is carried out with

Aa thermometer

Ba bomb calorimeter

Can evaporating dish

Da boiling tube

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Question 384

waec 2010

Which of the following gases contains the highest number of atoms at s.t.p?

A6 moles of neon

B3 moles of oxygen

C2 moles of chlorine

D1 mole of ethane

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Question 385

waec 2010

A given volume of oxygen diffused through a porous partition in 8 seconds. How long would it take the same volume of carbon (IV) oxide to diffuse under the same condition? [C = 12.0, O = 16.0]

A5.8 seconds

B6.8 seconds

C9.4 seconds

D11.0 seconds

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Question 386

waec 2010

Which of the following apparatus can be used to measure accurately a specific volume of a liquid?

ABeaker

BConical flask

CMeasuring cylinder

DPipette

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Question 387

waec 2010

What is the volume occupied by 2 moles of ammonia at s.t.p?

A44.8 dm^-3

B22.4 dm^-3

C11.2 dm^-3

D5.6 dm^-3

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Question 388

waec 2010

A solution of sodium trioxocarbonate (IV) contains 10.6g in 250cm³ of solution. Calculate the concentration of the solution. [Na₂CO₃ = 106.0]

A0.4 mol dm^-3

B1.0 mol dm^-3

C10.6 mol dm^-3

D25.0 mol dm^-3

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Question 389

waec 2010

Consider the neutralization reaction represented by the following equation: Na2CO3 + 2HNO 3 → 2NaNO3 + H2O + CO2 The stoichiometric ratio of acid to base is

A2:2

B2:1

C1:2

D1:1

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Question 390

waec 2010

The bonds in crystaline ammonium chloride are?

Acovalent and dative

Bionic and covalent

Cionic covalent and dative

Dionic covalent and hydrogen bond

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