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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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2,505 questions

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Question 391

jamb 2015

Atomicity of ozone is

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Question 392

jamb 2015

When salt loses its water of crystallization to the atmosphere on exposure, the process is said to be

Aefflorescence

Bdéliquescence

Ceffervescence

Dfluorescence

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Question 393

jamb 2015

A small quantity of solid ammonium chloride (NH4Cl) heated gently in a test tube, the solid gradually disappear produce two gases. Later, a white cloudy deposit was absence on the cooler part of the test tube. The ammonium chloride is to have undergo

Adistillation

Bsublimation

Cprecipitation

Devaporation

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Question 394

jamb 2015

The acid in electrolysis of water is dilute

AHNO₃

BCH₃COOH

CH₂SO₄

DHCl

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Question 395

jamb 2015

Vulcanization involve the removal of

Amonometer

Bthe single bond

Cthe double bond

Da polymer

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Question 396

jamb 2015

The gas that is most useful in protecting humans against solar marathon is

Achlorine

Bozone

Ccarbon IV oxide

Dhydrogen sulphide

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Question 397

jamb 2015

In the industrial production of H2 from water gas the CO2 produced along with the H2 is removed by

Awashing under pressure

Bdrying over phosphorus (V) oxide

Cpassing the mixture to the limewater

Dusing ammonical copper (I) chlorine

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Question 398

jamb 2015

Iron is often galvanized in order to

AMake it more malleable

BRemove the impurities unit

CProtect it against corrosion

DRender it passive

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Question 399

jamb 2015

Which of these require crystallization most?

ADrug making

BCement making

CPaint making

DPerfume making

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Question 400

jamb 2015

The filter in the cigarette reduce the nicotine construct by

Aburning

Badsorption

Cevaporation

Dabsorption

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Question 401

jamb 2014

Z in diagram above represents

Aheat of reaction

Bactivation energy

Cfree energy

Dentropy of reaction

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Question 402

jamb 2014

In the diagram, the function of the concentrated H2SO4 is to?

Apurify the gas

Bdry the gas

Cliquefty the gas

Dremove odour

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Question 403

jamb 2014

The IUPAC nomenclature of the compound above is

A2-bromo-3-chlorobutanol

B3-bromo-2-chlorobutanol

C3-chloro-2-bromobutanol

D2-chloro-3-bromobutanol

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Question 404

jamb 2014

The petroleum fraction that is used in heating furnaces in industries is

Adiesel oil

Bgasoline

Ckerosene

Dlubricating oil

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Question 405

jamb 2014

The process of converting linear alkanes to branched chain and cyclic hydrocarbons by heating in the presence of a catalyst to improve the quality of petrol is referred to as

Arefining

Bcracking

Creforming

Dblending

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Question 406

jamb 2014

Polystyrene is widely used as packaging materials for fragile objects during transportation because of its

Alightness

Blow density

Chigh density

Dhigh compressibility

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Question 407

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

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Question 408

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

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Question 409

jamb 2014

The polymer used in making car rear lights is

Aperspex

Bbakeelite

Cpolystyrene

Dpolyacrylonitrile

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Question 410

jamb 2014

The process of converting starch to ethanol is

Acracking

Bdistillation

Cfermentation

Doxidation

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