NECO SSCE - Chemistry - 2003

Tazama Jibu

Swali 2 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Electrolysis (JAMB)

Soma maelezo ya somo kwenye Acids, Bases And Salts (Ghana Only) (WAEC)

Electrolysis

Tazama Jibu

Swali 3 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Organic Compounds (JAMB)

Organic Compounds

Tazama Jibu

Swali 4 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

Chemistry Of Carbon Compounds (Nigeria Only)

Tazama Jibu

Swali 5 Ripoti

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

\( \text{0} \)

Maelezo ya Majibu

Soma maelezo ya somo kwenye Atomic Structure And Bonding (JAMB)

Tazama Jibu

Swali 6 Ripoti

What is formed when starch is completely hydrolysed?

fructose

glucose

lactose

maltose

sucrose

Maelezo ya Majibu

Soma maelezo ya somo kwenye Kinetic Theory Of Matter And Gas Laws (JAMB)

Soma maelezo ya somo kwenye Oxidation And Reduction (JAMB)

Soma maelezo ya somo kwenye Acids, Bases And Salts (Ghana Only) (WAEC)

Oxidation And Reduction

Tazama Jibu

Swali 7 Ripoti

What mass of copper is deposited when 6.5g of granulated zinc reacts with excess copper(II) tetraoxosulphate(VI) solution?

The equation for the reaction is: Zn(s) + \( CuSO_4(aq)→ ZnSO_4(aq)+ Cu(s)\)[CU= 64; Zn=65]

3.2 g

3.25 g

6.4 g

6.5 g

64.0 g

Maelezo ya Majibu

Soma maelezo ya somo kwenye Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

Tazama Jibu

Swali 8 Ripoti

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.

Maelezo ya Majibu

Soma maelezo ya somo kwenye Kinetic Theory Of Matter And Gas Laws (JAMB)

Soma maelezo ya somo kwenye Separation Of Mixtures And Purification Of Chemical Substances (JAMB)

Separation Of Mixtures And Purification Of Chemical Substances

Tazama Jibu

Swali 9 Ripoti

Which metal is extracted from bauxite?

aluminium

calcium

copper

magnesium

tin

Maelezo ya Majibu

Soma maelezo ya somo kwenye Metals And Their Compounds (JAMB)

Metals And Their Compounds

Tazama Jibu

Swali 10 Ripoti

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)

0.25

0.05

0.025

0.01

Maelezo ya Majibu

Soma maelezo ya somo kwenye Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

Tazama Jibu

Swali 11 Ripoti

Which element is the most electronegative?

calcium

fluorine

iodine

oxygen

sodium

Maelezo ya Majibu

Soma maelezo ya somo kwenye Atomic Structure And Bonding (JAMB)

Tazama Jibu

Swali 12 Ripoti

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.

Maelezo ya Majibu

Soma maelezo ya somo kwenye Acids, Bases And Salts (JAMB)

Soma maelezo ya somo kwenye Oxidation And Reduction (JAMB)

Acids, Bases And Salts

Oxidation And Reduction

Tazama Jibu

Swali 13 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Stoichiometry And Chemical Reactions (WAEC)

Stoichiometry And Chemical Reactions

Tazama Jibu

Swali 14 Ripoti

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

0.1

0.3

2.7

Maelezo ya Majibu

Soma maelezo ya somo kwenye Electrolysis (JAMB)

Electrolysis

Tazama Jibu

Swali 15 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Chemical Combination (JAMB)

Chemical Combination

Tazama Jibu

Swali 16 Ripoti

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.

Maelezo ya Majibu

Soma maelezo ya somo kwenye Chemical Bonds (Nigeria Only) (WAEC)

Soma maelezo ya somo kwenye Energy And Energy Changes (WAEC)

Chemical Bonds (Nigeria Only)

Energy And Energy Changes

Tazama Jibu

Swali 17 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Water (JAMB)

Water

Tazama Jibu

Swali 18 Ripoti

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)

Maelezo ya Majibu

Soma maelezo ya somo kwenye Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

Tazama Jibu

Swali 19 Ripoti

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

CH₃CH₂CHO

CH₃CH₂CH2OH

CH₃CH₂COQH

CH₃CH₂0CH

CH₃CH₃OH

Maelezo ya Majibu

Tazama Jibu

Swali 20 Ripoti

The reaction C₂H₆ → C₂H + H₂ is known as

dehydration

dehydrogenation

displacement

hydrogenation

reduction

Maelezo ya Majibu

Soma maelezo ya somo kwenye Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

Chemistry Of Carbon Compounds (Nigeria Only)

Tazama Jibu

Swali 21 Ripoti

Which separation technique is routinely applied in the petroleum industry?

chromatography

distillation

evaporation

fractional crystallization

fractional distillation

Maelezo ya Majibu

Soma maelezo ya somo kwenye Separation Of Mixtures And Purification Of Chemical Substances (JAMB)

Separation Of Mixtures And Purification Of Chemical Substances

Tazama Jibu

Swali 22 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Acids, Bases And Salts (Ghana Only) (WAEC)

Soma maelezo ya somo kwenye Periodic Chemistry (Ghana Only) (WAEC)

Periodic Chemistry (Ghana Only)

Tazama Jibu

Swali 23 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Atomic Structure And Bonding (JAMB)

Soma maelezo ya somo kwenye Chemical Equilibra (JAMB)

Chemical Equilibra

Tazama Jibu

Swali 24 Ripoti

Which is NOT a synthetic polymer?

nylon

Orion

Perspex

polystyrene

wool

Maelezo ya Majibu

Soma maelezo ya somo kwenye Basic Biochemistry And Synthetic Polymers (WAEC)

Basic Biochemistry And Synthetic Polymers

Tazama Jibu

Swali 25 Ripoti

What is the change in the oxidation number of phosphorus in the following reaction?

4P(s) + 5O₂(ag) → 2P₂O₅(s)

0 to 2

0 to 5

4 to 2

4 to 5

4 to 10

Maelezo ya Majibu

Soma maelezo ya somo kwenye Oxidation And Reduction (JAMB)

Oxidation And Reduction

Tazama Jibu

Swali 26 Ripoti

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

CH₄

C₂H₆

C₃H₆

C₃H₈

C₆H₆

Maelezo ya Majibu

Soma maelezo ya somo kwenye Chemistry Of Carbon Compounds (Ghana Only) (WAEC)

Chemistry Of Carbon Compounds (Ghana Only)

Tazama Jibu

Swali 27 Ripoti

Which metal bromide is widely used in photography?

calcium bromide

magnesium bromide

potassium bromide

silver bromide

sodium bromide

Maelezo ya Majibu

Soma maelezo ya somo kwenye Metals And Their Compounds (JAMB)

Metals And Their Compounds

Tazama Jibu

Swali 28 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Chemical Kinetics And Equilibrium System (Nigeria Only) (WAEC)

Soma maelezo ya somo kwenye Electrolysis (JAMB)

Chemical Kinetics And Equilibrium System (Nigeria Only)

Electrolysis

Tazama Jibu

Swali 29 Ripoti

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

6.8

6.9

7.1

Maelezo ya Majibu

Soma maelezo ya somo kwenye Kinetic Theory Of Matter And Gas Laws (JAMB)

Soma maelezo ya somo kwenye Atomic Structure And Bonding (JAMB)

Tazama Jibu

Swali 30 Ripoti

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Kinetic Theory Of Matter And Gas Laws (JAMB)

Soma maelezo ya somo kwenye Acids, Bases And Salts (Ghana Only) (WAEC)

Tazama Jibu

Swali 31 Ripoti

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.

Maelezo ya Majibu

Soma maelezo ya somo kwenye Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

Chemistry Of Carbon Compounds (Nigeria Only)

Tazama Jibu

Swali 32 Ripoti

The pH of water is 7.

What is the pH of orange juice?

above 10

below 2

between 5.5 and 6.5

between 7.5 and 8.5

Maelezo ya Majibu

Soma maelezo ya somo kwenye Acids, Bases And Salts (Ghana Only) (WAEC)

Tazama Jibu

Swali 33 Ripoti

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]

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

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

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

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

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

Maelezo ya Majibu

Soma maelezo ya somo kwenye Kinetic Theory Of Matter And Gas Laws (JAMB)

Tazama Jibu

Swali 34 Ripoti

Which metal is a constituent of both bronze and solder?

copper

lead

silver

tin

zinc

Maelezo ya Majibu

Soma maelezo ya somo kwenye Metals And Their Compounds (JAMB)

Metals And Their Compounds

Tazama Jibu

Swali 35 Ripoti

In the reaction 2H₂S(g) + SO₂(g) → 2H₂SO(I)+3S(s)SO₂is acting as _agent

a bleaching

a dehydrating

an oxidizing

a precipitating

a reducing

Maelezo ya Majibu

Soma maelezo ya somo kwenye Kinetic Theory Of Matter And Gas Laws (JAMB)

Soma maelezo ya somo kwenye Oxidation And Reduction (JAMB)