JAMB UTME - Chemistry - 2020 | Green Bridge CBT

Question 1 Report

If the quantity of oxygen occupying 2.76L container at a pressure of 0.825 atm and 300k is reduced by one-half, what is the pressure exerted by the remaining gas?

1.650atm

0.825atm

0.413atm

0.275atm

Answer Details

Using the combined gas law formula,

Given that P $_{1}$ = 0.825, V $_{1}$ = 2.76 L, V $_{2}$ = 1.38 L, P $_{2}$ = ?

And T1 = T2; we would have P $_{2}$ = [ P $_{1}$ X V $_{1}$ ] / V $_{2}$

: [0.825 X 2.76] / 1.38

= 1.650atm

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 2 Report

What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?

24,125 C

48,250 C

72,375 C

96,500 C

Answer Details

4OH ⇒ 2H $_{2}$ O + O $_{2}$ + 4e-

From the equation:

1 mole of Oxygen requires 4e

i.e 1 mole of Oxygen requires 4F,

where 1F = 96,500 C

[ 4 X 96,500 X 0.125 ] ÷ 1

= 48,250 C

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Question 3 Report

The electronic configuration of an element is $1S^2$ $2S^2$ $2P^6$ $3S^2$ $3P^3$. How many unpaired electrons are there in the element?

5

4

3

2

Atomic Structure And Bonding

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Question 4 Report

A few drop of conc HCL are added to about $10\text{cm}^{3}$ of a solution of PH 3.4. The PH of the resulting mixture is

less than 3.4

greater than 3.4

unaltered

the same as that of the pure water

Acids, Bases And Salts

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Question 5 Report

The most important element on the earth's crust is?

Nitrogen

Hydrogen

Oxygen

Fluorine

Structure Of The Atom

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Question 6 Report

The products of the thermal decomposition of ammonium trioxonitrate(v) are?

Nitrogen (I) Oxide and Water

Ammonia and Oxide

Nitrogen and Water

Nitrogen (IV) Oxide and Water

Answer Details

NH

_{4}

NO

_{3}

Ammonium Trioxonitrate(V) , unlike all other metallic trioxonitrates(v), decomposes on heating to give nitrogen(i)oxide N

_{2}

O and water.

Read lesson note on Acids, Bases And Salts (Nigeria Only) (WAEC)

Acids, Bases And Salts (Nigeria Only)

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Question 7 Report

The chlorinated alkane often used industrially to remove grease is?

Tetrachloromethane

Chloromethane

Trichloromethane

Dichloromethane

Chemistry Of Carbon Compounds (Nigeria Only)

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Question 8 Report

When water drops are added to calcium carbide in a container and the gas produced is passed through a jet and lighted, the resultant flame is called an?

Oxyethene

Oxyhydrocarbon flame

Oxyacetylene flame

Oxymethane flame

Periodic Chemistry (Ghana Only)

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Question 9 Report

The general formula for the Alkanals is?

R

_{2}

CO

RCHO

ROH

RCOOR

Periodic Chemistry (Ghana Only)

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Question 10 Report

Aluminum hydroxide is used in the dyeing industry as a?

Dye

Dispersant

Salt

Mordant

Acids, Bases And Salts

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Question 11 Report

8g of $ \mathrm{CH_4} $ occupies 11.2 at S.T.P. What volume would 22g of $ \mathrm{CH_3CH_2CH_3} $ occupy under the same condition?

3.7dm

^{3}

11.2dm

^{3}

22.4dm

^{3}

33dm

^{3}

Stoichiometry And Chemical Reactions

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Question 12 Report

Which of the following gases will rekindle a brightly splint?

NO

_{2}

NO

N

_{2}

O

CL

_{2}

Kinetic Theory Of Matter And Gas Laws

Separation Of Mixtures And Purification Of Chemical Substances

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Question 13 Report

An organic compound that does not undergo a reaction with both hydrogen cyanide and hydroxylamine can be?

Alkene

Alkanal

Alkanone

Alkanoic Acid

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Question 14 Report

Four elements P, Q, R and S have atomic numbers of 4, 10, 12 and 14 respectively. Which of these elements is noble gas?

P

Q

R

S

Structure Of The Atom

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Question 15 Report

An electron can be added to a halogen atom to form a halide ion with?

8 valence electrons

7 valence electrons

2 valence electrons

3 valence electrons

Answer Details

A halide ion is a halogen atom bearing a negative charge (which is an anion with a charge of -1). The halide anions are fluoride (F

^{-}

), chloride (Cl

^{-}

), bromide (Br

^{-}

), iodide (I

^{-}

) and astatide (At

^{-}

).

Read lesson note on Atomic Structure And Bonding (JAMB)

Atomic Structure And Bonding

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Question 16 Report

What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke?

Steam distillation

Destructive distillation

Liquefication

Hydrolysis

Chemical Combination

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Question 17 Report

How many valence electrons are contained in the element $ {}_{15}^{31}\mathrm{P} $?

3

4

15

31

Structure Of The Atom

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Question 18 Report

The number of molecules of Carbon(iv)Oxide produced when 10.0g of $ \mathrm{CaCO_3} $ is treated with $0.2\mathrm{dm^3}$ of 1 Mole of HCL in the equation

\[ \mathrm{CaCO_3 + 2HCL \rightarrow CaCl_2 + H_2O + CO_2} \], is ?

1.00 X 10

^{23}

6.02 X 10

^{23}

6.02 X 10

^{22}

6.02 X 10

^{24}

Stoichiometry And Chemical Reactions

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Question 19 Report

An example of a polysaccharide is?

Dextrose

Mannose

Glucose

Starch

Basic Biochemistry And Synthetic Polymers

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Question 20 Report

Which of the following can be obtained by fractional distillation?

Nitrogen from liquid air

Sodium Chloride from sea water

Iodine from solution of Iodine in carbon tetrachloride

Sulphur from the solution of sulphur in carbon disulphide

Solubility

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Question 21 Report

Chromatography is used to separate components of mixture which differ in their rates of ?

diffusion

migration

reaction

sedimentation

Separation Of Mixtures And Purification Of Chemical Substances

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Question 22 Report

Which of the following types of bonding does not involve the formation of new substances?

Metallic

Covalent

Co-ordinate

Electrovalent

Atomic Structure And Bonding

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Question 23 Report

What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

8.0g

16.0g

36.0g

72.0g

Answer Details

2H

_{2}

+ O

_{2}

\to

2H

_{2}

O
From the equation:4g of Hydrogen produces 36g of water: 8g of Hydrogen will produce 72g of water

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

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Question 24 Report

To obtain pure carbon(ii)oxide from its mixture with carbon(iv)oxide, the mixture should be?

Passed over heated copper(ii)oxide

Bubbled through water

Bubbled through conc H

_{2}

SO

_{4}

Bubbled through conc NAOH

Answer Details

carbon(ii)oxide is prepared from carbon(iv)oxide by passing the latter through red-hot carbon and the unchanged CO

_{2}

is removed when the mixture of the gases through conc NAOH.

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 25 Report

Which of the following substances is a mixture?

Granulated sugar

Seawater

Sodium chloride

Iron filling

Separation Of Mixtures And Purification Of Chemical Substances

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Question 26 Report

Liquid black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the ?

Acid

Ester of alkanoic acid

Alkali

Acids, Bases And Salts

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Question 27 Report

When a solid substance disappears completely as a gas on heating, the substance is said to have undergone?

Sublimation

Crystallization

Distillation

Evaporation

States Of Matter

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Question 28 Report

32g of anhydrous copper(ii)tetraoxosulphate(vi) dissolved in $1\mathrm{dm}^3$ of water generated 13.0kj of heat. The heat solution is?

26.0kj/mol

65.0kj/mol

130.0kj/mol

260.0kj/mol

Answer Details

32g of CUSO

_{4}

liberate 13.0kj of heatMolar mass of CUSO

_{4}

= 160gNo. of moles of CUSO

_{4}

= 32gNo. of moles = 32(mass) / 160(molar mass)= 0.2 molesi.e 0.2 = 13kj1 moles = xkj: 65KJ

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 29 Report

Proteins in acid solution undergo?

Substitution

Fermentation

Hydrolysis

Polymerisation

Acids, Bases And Salts

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Question 30 Report

A gaseous metallic chloride MCl consists of 20.22% of M by mass. The formula of the chloride is?

[ M = 27, Cl = 35.5]

MCl

_{2}

MCl

_{3}

M

_{2}

Cl

_{6}

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Question 31 Report

What are the possible oxidation numbers of an element if its atomic number is 17?

-1 and 7

-1 and 6

-3 and 5

-2 and 6

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Question 32 Report

Duralumin consists of aluminum, copper?

Zinc and Gold

Lead and Manganese

Nickel and Silver

Manganese and Magnesium

Metals And Their Compounds

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Question 33 Report

Which of the gas laws does this graph illustrate?

Boyle

Charles

Gay-Lussac

Graham

Kinetic Theory Of Matter And Gas Laws

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Question 34 Report

When cathode rays are deflected onto the electrode of an electrometer, the instrument becomes?

Bipolar

Negatively charged

Positively charged

Neutral

Structure Of The Atom

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Question 35 Report

Deliquescent substances are also?

efflorescent

anhydrous

hygroscopic

insoluble

Solubility Of Substances (Ghana Only)

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Question 36 Report

The volume occupied by 1.58g of a gas at S.T.P is 500cm$^{3}$. What is the relative molecular mass of the gas? [ G.M.V at S.T.P = 22.4dm$^{3}$ ]

28

32

44

71

Kinetic Theory Of Matter And Gas Laws

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Question 37 Report

The best treatment for a student who accidentally poured conc tetraoxosulphate(vi) on his skin in the laboratory is to wash his skin with?

with cool running water

sodium hydroxide solution

iodine solution

sodium trioxonitrate(v) solution

Acids, Bases And Salts (Ghana Only)

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Question 38 Report

The substance often used for vulcanization of rubber is?

Chlorine

Hydrogen peroxide

Sulphur

Tetraoxosulphate(vi) acid

Chemistry Of Carbon Compounds (Ghana Only)

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Question 39 Report

The shape of ammonia molecule is?

Trigonal planar

Octahedral

Square planar

Tetrahedral

Structure Of The Atom (Ghana Only)

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Question 40 Report

Helium is used in observation of ballons because it is?

Light and combustible

light and non-combustible

heavy and combustible

heavy and non-combustible

Kinetic Theory Of Matter And Gas Laws

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	M	Cl
% composition	20.22	79.78
Atomic mass	27	35.5
Mole ratio	20.22	79.78
	27	35.5
	0.75	2.25
Divided	0.75	0.75
	1	3






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JAMB UTME - Chemistry - 2020

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