Chemistry JAMB, WAEC, NECO AND NABTEB Official Past Questions

211

Why is water often referred to as the “universal solvent”?

  • A. Water is the most abundant substance on Earth
  • B. Water is essential for all living organisms.
  • C. Water is involved in many chemical reactions
  • D. Water can dissolve a wide variety of substances due to its polar nature
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212

Benzene can be converted to its derivative toluene by the addition of a methyl group. The reaction is an example of

  • A. Nucleophilic substitution
  • B. Elimination reaction
  • C. Electrophilic substitution
  • D. Addition reaction
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213

What is the main environmental concern associated with sulfur dioxide emissions?

  • A. Formation of acid rain
  • B. Global warming potential
  • C. Depletion of the stratospheric ozone
  • D. Depletion of the ozone layer
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214

At 2.0 atm pressure, the volume of a gas is 4.0 L. If the pressure is reduced to 1.0 atm while keeping the temperature constant, what will be the new volume of the gas?

  • A. 2.0 L
  • B. 6.0 L
  • C. 8.0 L
  • D. 4.0 L
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215

Which functional group is present in alkanals?

  • A. Carbonyl group (C=O)
  • B. Hydroxyl group (-OH)
  • C. Alkyl group (-R)
  • D. Carboxyl group (-COOH)
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216

What happens when alkanoic acids react with alcohols in the presence of an acid catalyst?

  • A. Saponification
  • B. Esterification
  • C. Polymerization
  • D. Hydrolysis
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217

Which of the following metals is commonly alloyed with copper to make brass?

  • A. Iron
  • B. Nickel
  • C. Aluminum
  • D. Zinc
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218

What is the atomic number of aluminium?

  • A. 13
  • B. 26
  • C. 14
  • D. 12
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219

Which type of salt is found in antacid medications and is used to relieve heartburn and indigestion?

  • A. Aluminum chloride
  • B. Magnesium chloride
  • C. Sodium chloride
  • D. Calcium chloride
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220

When anhydrous cobalt chloride paper is exposed to water, what color change is observed?

  • A. From pink to blue
  • B. From white to blue
  • C. From blue to white
  • D. From blue to pink
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221

What is the valency of an element with the electronic configuration 2, 8, 7?

  • A. 7
  • B. 1
  • C. 2
  • D. 3
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222

Which of the following methods is commonly used to remove suspended impurities from water?

  • A. Fluoridation
  • B. Chlorination
  • C. Filtration
  • D. Distillation
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223

Which transition metal is known for its multiple colorful oxidation states and compounds used in pigments and paints?

  • A. Silver (Ag)
  • B. Copper (Cu)
  • C. Gold (Au)
  • D. Zinc (Zn)
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224

Which element is placed at the top of the electrochemical series?

  • A. Copper
  • B. Hydrogen
  • C. Sodium
  • D. Oxygen
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225

Isotopes of an element have

  • A. The same number of protons but different numbers of neutrons.
  • B. The same number of neutrons and electrons
  • C. The same number of protons and neutrons
  • D. The same number of protons and electrons
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226

What is the molecular geometry of a molecule with three bonding pairs and no lone pairs around the central atom?

  • A. Tetrahedral
  • B. Trigonal planar
  • C. Linear
  • D. Octahedral
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227

At room temperature and standard pressure, chlorine gas is in which state of matter?

  • A. Plasma
  • B. Solid
  • C. Liquid
  • D. Gas
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228

Sodium reacts vigorously with water to produce

  • A. Sodium chloride (NaCl) and oxygen gas (O2)
  • B. Sodium nitrate (NaNO3) and water (H2O)
  • C. Sodium hydroxide (NaOH) and hydrogen gas (H2)
  • D. Sodium oxide (Na2O) and hydrogen gas (H2)
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229

Which of the following is a unique property of water compared to other liquids?

  • A. It is a poor solvent
  • B. It does not evaporate
  • C. It expands when freezing
  • D. It has a low heat capacity
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230

The contact process is used for the industrial production of

  • A. sulfuric acid (H2SO4)
  • B. Hydrochloric acid (HCl)
  • C. Sodium hydroxide (NaOH)
  • D. Calcium oxide (CaO)
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231

If gas A has a molar mass of 32 g/mol and gas B has a molar mass of 64 g/mol, what is the ratio of their diffusion rates?

  • A. 2:1
  • B. 1:2
  • C. 1:1
  • D. 1:4
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