JAMB Chemistry 2024

Which of the following elements will exhibit the most electronegative character?

(a) Al (b) Si (c) P (d) S

Correct Answer: (d) S

Acid hydrolysis of nitriles will yield?

(a) Alkanes (b) Aldehydes (c) Carboxylic acids (d) Alcohols

Correct Answer: (c) Carboxylic acids

How many isomers of C₄H₉OH will be tertiary alkanol?

(a) 1 (b) 2 (c) 3 (d) 4

Correct Answer: (b) 2

Which of the following makes oils distinguished from fats?

(a) Oil contains a higher proportion of unsaturation (b) Fats contain a higher proportion of unsaturation (c) Oil and fats have the same proportion of unsaturation (d) Neither oil nor fats have unsaturation

Correct Answer: (a) Oil contains a higher proportion of unsaturation

The characteristic crystalline shape of solid water is due to _____

(a) Covalent bonds (b) Hydrogen bonds (c) Ionic bonds (d) Metallic bonds

Correct Answer: (b) Hydrogen bonds

The chemical formula for laughing gas is _____

(a) NO (b) NO₂ (c) N₂O (d) N₂O₅

Correct Answer: (c) N₂O

The sulphide used in coating electric fluorescent tubes is _____

(a) Iron (II) sulphide (b) Sphalerite (c) Zinc sulphide (d) Sulphide mineral

Correct Answer: (c) Zinc sulphide

Calculate the volume in dm³ of oxygen evolved at s.t.p. When a current of 5A is passed through acidified water for 772s (molar volume of gas at stp. = 22.4 dm³)

(a) 0.056 (b) 0.224 (c) 224000 (d) 56000

Correct Answer: (b) 0.224

Hydrogenation of Benzene to cyclohexane is called

(a) Cracking (b) Polymerisation (c) Reforming (d) Aromatization

Correct Answer: The examiner had aromatization in mind but it does not apply

The pollutant that contributes to the depletion of the ozone layer is _____

(a) CF (b) CS (c) CCl (d) CFC

Correct Answer: (d) CFC

What changes sodium hydroxide pellets to liquid?

(a) Oxygen (b) Water vapour (c) Carbon (IV) oxide (d) Nitrogen

Correct Answer: (b) Water vapour

The compound used as 'antifreeze' in car radiators in cold regions of the world is _____

(a) Ethanol (b) Ethylene glycol (c) Ethanal (d) Propan-1,2-diol

Correct Answer: (b) Ethylene glycol

What are the laws that form the general gas equation?

(a) Boyle's and Charles' laws (b) Boyle's Charles' and Graham's laws (c) Gaps between the coils (d) The area of the coil

Correct Answer: (a) Boyle's and Charles' laws

Chlorine, bromine, and iodine resemble each other in that all

(a) Dissolve in alkalis (b) Displace each other from solutions of their salts (c) React violently with hydrogen on heating (d) Are electron donors

Correct Answer: (a) Dissolve in alkalis

The method suitable for separating suspended particles in liquid is _____

(a) Decantation (b) Distillation (c) Centrifugation (d) Chromatography

Correct Answer: (c) Centrifugation

A hydrocarbon X has a molar mass of 26 and a carbon atom percentage of 92.3%. What is its molecular formula?

(a) C₂H₂ (b) C₂H₆ (c) CH₄ (d) C₃H₈

Correct Answer: (a) C₂H₂

Silica gel, when exposed to air, turns liquid. What kind of substance is it?

(a) Deliquescent (b) Hygroscopic (c) Efflorescent (d) Entropy

Correct Answer: (a) Deliquescent

In an equilibrium reaction, which of the following conditions indicate that the maximum yield of the product will be obtained?

(a) Equilibrium constant is very large (b) △H=T△S (c) ΔH≥TΔS (d) Equilibrium constant is less than zero

Correct Answer: (a) Equilibrium constant is very large

Under high pressure, real gases do not obey laws because their molecules

(a) Have become more energetic (b) Have become less energetic (c) Have become smaller in size (d) Have become larger in size

Correct Answer: (b) Have become less energetic

The salt responsible for temporary hardness is _____

(a) Calcium sulphate (b) Magnesium chloride (c) Calcium bicarbonate (d) Magnesium sulphate

Correct Answer: (c) Calcium bicarbonate

Common salt (NaCl) is used to preserve foods. Which of the following properties can be used to determine its purity before use?

(a) Solubility in water (b) Melting point (c) Relative density (d) Crystalline nature

Correct Answer: (b) Melting point

The rate of a chemical reaction is NOT affected by one of these factors

(a) Color (b) Concentration (c) Presence of light (d) Surface area

Correct Answer: (a) Color

The functional group represented in the compound below is _____

(a) Alkanol (b) Alkanal (c) Alkanone (d) Alkanoate

Correct Answer: (b) Alkanal

On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as _____

(a) Efflorescence (b) Deliquescence (c) Hydroscopy (d) Hydrolysis

Correct Answer: (a) Efflorescence

Which of the following statements is true of the electrochemical series?

(a) Electropositivity of metals increases down the series (b) Electropositivity of non-metals decreases down the series (c) Electronegativity of non-metals decreases (d) Electropositivity of metals decreases down the series

Correct Answer: (d) Electropositivity of metals decreases down the series

Which of the following pairs are both substances deliquescent?

(a) CaCl₂ and H₂SO₄ (b) NaOH and MgSO₄.7H₂O (c) CaCl₂ and NaOH (d) CuO and NaCl

Correct Answer: (c) CaCl₂ and NaOH

The bond formed between H₂O and H⁺ to form the hydroxonium H₃O⁺ is

(a) Dative (b) Covalent (c) Electrovalent (d) Ionic

Correct Answer: (a) Dative

Gas molecules are said to be perfectly elastic because

(a) They collide without loss of energy (b) They move about in straight lines (c) The distances between them are neglible (d) The volume occupied by them is negligible

Correct Answer: (a) They collide without loss of energy

A solid that absorbs water from the atmosphere and forms an aqueous solution is _____

(a) Hydrophilic (b) Efflorescent (c) Deliquescent (d) Hygroscopic

Correct Answer: (c) Deliquescent

Which of the following can undergo both addition reaction and substitution reaction?

(a) Benzene (b) Pentane (c) Propane (d) Hexane

Correct Answer: (a) Benzene

Naming of the organic compound CH₃(CH₂)₄CH₂CH₂NH₂

(a) Pentaneamine (b) Heptanamine (c) Hexanamine (d) Octanamine

Correct Answer: (b) Heptanamine

2Cl^-(aq) = Cl₂(g) + 2e^-(aq)

The above half-cell reaction occurring at the anode during the electrolysis of dilute ZnCl₂ solution is?

(a) Ionization (b) Oxidation (c) Reduction (d) Recombination

Correct Answer: (b) Oxidation

CHCl₃ + Cl₂ → HCl + CCl₄

The reaction above is an example of?

(a) An addition reaction (b) A decomposition reaction (c) A substitution reaction (d) A condensation reaction

Correct Answer: (c) A substitution reaction

C_xH_y + 4O₂ = 3CO₂ + 2H₂O. The hydrocarbon, C_xH_y, in the reaction above is?

(a) Butene (b) Butane (c) Butyne (d) Butanone

Correct Answer: (b) Butane

One method of driving the position of equilibrium of an endothermic reaction forward is to?

(a) Increase temperature at constant pressure (b) Decrease pressure at constant temperature (c) Cool down the apparatus with water (d) Decreases temperature at constant pressure

Correct Answer: (a) Increase temperature at constant pressure

0.92 of ethanol when burned raised the temperature of 50g of water by 28.6K. Calculate the heat of combustion of ethanol. [C = 12, O = 16, H = 1, specific heat capacity of water = 4.2Jg^-1K^-1]

(a) +3000KJmol^-1 (b) +300KJmol^-1 (c) -300KJmol^-1 (d) -3000KJmol^-1

Correct Answer: (c) -300KJmol^-1

The repeating unit in natural rubber is _____

(a) Alkyne (b) Isoprene (c) n-propene (d) neoprene

Correct Answer: (b) Isoprene

What current in amperes will deposit 2.7g of aluminium in 2 hours? [Al = 27, F = 96500Cmol^-1]

(a) 32 (b) 8 (c) 4 (d) 16

Correct Answer: (c) 4

Steam changes the colour of anhydrous cobalt (II) choloride from

(a) Blue to pink (b) Red to white (c) White to green (d) White to blue

Correct Answer: (a) Blue to pink

Which of the following will change when a catalyst is added to a chemical reaction?

(a) The activation energy (b) The potential energy of the reactants (c) The heat of the reaction (d) The potential energy of the product

Correct Answer: (a) The activation energy