NECO SSCE - Chemistry - 2003

Oxidation And Reduction

Wo Idahun

Ibeere 4 Ìròyìn

What is the concentration (in mol dm³) of a solution containing 28 g of potassium hydroxide per 100 cm³ of solution? (K=39; H=1; 0=16)

0.01

0.05

0.1

0.5

2.8

Wo Idahun

Ibeere 5 Ìròyìn

Chlorine displaces bromine from aqueous potassium bromide because

bromine is a liquid at room temperature

bromine is weakly acidic.

bromine has a greater atomic radius than chlorine

chlorine is a stronger oxidising agent than bromine.

the density of chlorine is less than the density of bromine.

Separation Of Mixtures And Purification Of Chemical Substances

Wo Idahun

Ibeere 6 Ìròyìn

What is the number of moles of NaHCO₃in 250cm³ of its solution if the solution contains 8.4 g of NaHCO₃ in 1 dm³ of the solution. [Na = 23, 0 = 16, C = 12, H = 1)

1

0.25

0.05

0.025

0.01

Stoichiometry And Chemical Reactions

Wo Idahun

Ibeere 7 Ìròyìn

Why is tetraoxosulphate(VI) acid NOT used for making carbon dioxide from calcium carbonate? It is

a dehydrating agent

a strong acid

an oxidising agent

dibasic

forms insoluble calcium tetraoxosulphate(Vl)

Acids, Bases And Salts

Wo Idahun

Ibeere 8 Ìròyìn

An organic compound gave the following results on analysis: C = 29.3% ; H = 5.7%; Br = 65%.
What is the empirical formula of the compound? [C = 12, H = 1, Br=80]

CH₃Br

C₂H₅Br

C₃H₅Br

C₃H₇Br

C₄H₉Br

Organic Compounds

Wo Idahun

Ibeere 9 Ìròyìn

Naturally occurring lithium consists of 90% $ ^7_3Li \text{ and 10% } ^6_3 Li. $ What is the relative atomic mass of lithium?

6

6.8

6.9

7

7.1

Wo Idahun

Ibeere 10 Ìròyìn

B is an isotope of the element $^{238} _{92}Ur$ . The isotope B has

46 protons and 119 neutrons

92 protons and 92 neutrons

92 protons and 146 neutrons

92 protons and 238 neutrons

Chemical Equilibra

Wo Idahun

Ibeere 11 Ìròyìn

Which metal is extracted from bauxite?

aluminium

calcium

copper

magnesium

tin

Metals And Their Compounds

Wo Idahun

Ibeere 12 Ìròyìn

Which element is the most electronegative?

calcium

fluorine

iodine

oxygen

sodium

Wo Idahun

Ibeere 13 Ìròyìn

At s.t.p, a mole of chlorine occupies 22.4dm³. If the temperature is changed to 35°C and the pressure to 750mHg the of the new volume will be [Cl = 35.5]

^{\text{760 x 22.4 x 308}} \text{750 x 273x 35.5} dm^3

^{\text{760 x 22.4 x 308}} \text{750 x 273}^x dm^3

^{\text{750 x 22.4 x 35.5}} \text{760 x 273dm3}

^{\text{760 x 22.4 x 35.5}} \text{750x22.3x273}

^{\text{760 x 22.4 x 35.5}} \text{750 x 308dm3}

Wo Idahun

Ibeere 14 Ìròyìn

The number of hydrogen ions in 1.0dm6.00x10³ of a 0.25 mole dm6.00x10^-3 tetraoxosulphate(Vl) acid solution is
[Avogadro constant = 6.0 x 1 0]

1.45x10²³

1.50 x l0²³

3.00x10²³

3.15x10²³

6.00x10²³

Stoichiometry And Chemical Reactions

Wo Idahun

Ibeere 15 Ìròyìn

Which statement is NOT true about the composition of starch?

It contains only the atoms of carbon, hydrogen oxygen

It is a polysaccharide

Its empirical formula is C₂H₂0.

It is made from the monomerC₆H₁₂O₆.

The hydrogen and oxygen atoms are in the ratio 2:1.

Wo Idahun

Ibeere 16 Ìròyìn

The boiling point of water is higher than the boiling point of ethanol because

the bonding in water is electrovalent (ionic) whereas the bonding in ethanol is convalent

the hydrogen bonding between water molecules is stronger than the hydrogen bonding between ethanol molecules

water has a higher lattice energy than ethanol.

water has hydrogen bonding between its molecules but ethanol has no hydrogen bonging between its molecules;

water is a better solvent than ethanol.

Chemical Bonds (Nigeria Only)

Energy And Energy Changes

Wo Idahun

Ibeere 17 Ìròyìn

Which formula is used to indicate the degree of acidity of an acid?

[H^+] = ^{\text{mass of acid relative}} molecular mass of acid

F = number of H+ = ions x molar mass of the acid

Kw = [H+][OH-]

pH = - log₁₀[H+]

pKa = -log₁₀Ka

Periodic Chemistry (Ghana Only)

Wo Idahun

Ibeere 18 Ìròyìn

Why does the treatment of cotton fabrics with dilute acids weaken the materials?

Cotton is hydrolysed completely to glucose

The fabrics are soluble in dilute acids

The molecular chains are partially broken

The molecular chain length f the fabric increases

The thread holding the fabric together Is completely destroyed.

Acids, Bases And Salts

Oxidation And Reduction

Wo Idahun

Ibeere 19 Ìròyìn

What is the IUPAC name of CH₃CCI=C(CH₃)2?

2-chloro -3 methylbut -2yne

2 -chloro -3 methylbut -2ene

2 -chloro -3 methylbutene

3- methyl -2-chlorobut -2-ene

3- methyl -2. chlorobut -2 yne

Wo Idahun

Ibeere 20 Ìròyìn

The reaction C₂H₆ → C₂H + H₂ is known as

dehydration

dehydrogenation

displacement

hydrogenation

reduction

Wo Idahun

Ibeere 21 Ìròyìn

How many Faradays of electricity are required to liberate 9g of aluminium? [Al = 27]

0.1

0.3

1

2.7

3

Electrolysis

Wo Idahun

Ibeere 22 Ìròyìn

Which is NOT a synthetic polymer?

nylon

Orion

Perspex

polystyrene

wool

Basic Biochemistry And Synthetic Polymers

Wo Idahun

Ibeere 23 Ìròyìn

Small amounts of compounds of transition metals are sometimes added to glass during manufacture in order to make the glass

acquire certain colours

easier to melt

easier to mould

little brittle

more transparent

Chemical Combination

Wo Idahun

Ibeere 24 Ìròyìn

What is formed when starch is completely hydrolysed?

fructose

glucose

lactose

maltose

sucrose

Oxidation And Reduction

Wo Idahun

Ibeere 25 Ìròyìn

A calcium atom and a calcium ion have the same

chemical properties

electric charge

electronic structure

number of electrons

number of neutrons

Wo Idahun

Ibeere 26 Ìròyìn

Chlorine is used in water purification because it

bleaches impurities in the water

decolorizes water

destroys bacteria

is extremely soluble in water

is pleasant tasting

Water

Wo Idahun

Ibeere 27 Ìròyìn

Which metal is a constituent of both bronze and solder?

copper

lead

silver

tin

zinc

Metals And Their Compounds

Wo Idahun

Ibeere 28 Ìròyìn

The pH of water is 7.

What is the pH of orange juice?

7

above 10

below 2

between 5.5 and 6.5

between 7.5 and 8.5

Wo Idahun

Ibeere 29 Ìròyìn

Which compound will give propane when it Is dehy drated by an excess of hot, concentrated tetraoxosvlphate(VI) acid?

CH₃CH₂CHO

CH₃CH₂CH2OH

CH₃CH₂COQH

CH₃CH₂0CH

CH₃CH₃OH

Wo Idahun

Ibeere 30 Ìròyìn

Which hydrocarbon does NOT exhibit structural isomerism?

C₃H₆

C₄H₆

C₄H₈

C₄H₁₀

C₅H₁₂

Wo Idahun

Ibeere 31 Ìròyìn

Ethene decolourises acidified potassium tetraoxomanganate(VII) solution. Which gas will decolourise bromine water?

CH₄

C₂H₆

C₃H₆

C₃H₈

C₆H₆

Chemistry Of Carbon Compounds (Ghana Only)

Wo Idahun

Ibeere 32 Ìròyìn

What change will occur to the equilibrium mixture
$2CrO^{2-}_4(aq) + 2H^+(aq) ⇔ Cr_2O^{2-}_7(aq) + H_2O(l)$ when excess sodium hydrogen solution is added?

A yellow precipitate of Cr(OH)₃ is formed

An orange precipitate of Cr(OH)₃ is formed

The colour changes from orange to yellow

The colour changes from yellow to orange

There is no visible reaction.

Chemical Kinetics And Equilibrium Systems (Ghana Only)

Structure Of The Atom

Wo Idahun

Ibeere 33 Ìròyìn

Which method is used for the purification of copper from its ore?

distillation

electrochemical

electrolysis

neutralization

reduction

Electrolysis

Wo Idahun

Ibeere 34 Ìròyìn

An atom of element X has an electronic configuration of $1s^22p^33s^23p^2.$ In which group of the periodic table is X?

\text{0}

2

3

4

5

Wo Idahun

Ibeere 35 Ìròyìn

What mass of silver is deposited when a current of 2.6 A is passed through a solution of a silver salt for 40 minutes? [Ag= 108 ; F=96500C]

6.89g

6.93g

6.98g

7.04g

7.12g

Chemical Kinetics And Equilibrium System (Nigeria Only)

Electrolysis

Wo Idahun

Ibeere 36 Ìròyìn

What change will occur during the electrolysis of brine using carbon electrodes?

Chlorine will be given off at the cathode

Oxygen gas will be given off at the anode

Sodium will be deposited at the cathode

The resulting solution, after electrolysis, will be acidic.

The volumes of hydrogen and chlorine given off during the same time are equal

Electrolysis