Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 1381: The isomers of C₃H₈O ARE Options:
  A) 1 - propanol and 2 - propanol
  B) 1 - propanol and 1 - propanol
  C) 2 - propanol and 2 - propanone
  D) 2 - propanol and 1 - propanol
  Show Answer
  The correct answer is A .
• Question 1382: What is the pH of 0.001 mol dm^-3 solution of sodium hydroxide Options:
  A) 14
  B) 13
  C) 12
  D) 11
  Show Answer
  The correct answer is D .
• Question 1383:

  Which of the following describes the chemical property of acids?

  Options:
  A) None of the above
  B) Acid + XCO${}_3$ $\to$ Salt + H${}_2$O + NH${}_3$
  C) Acid + NaOH $\to$ Normal salt + CO${}_2$
  D) Acid + X${}_n$CO${}_3$ $\to$ Salt + H${}_2$O + CO${}_2$
  Show Answer
  The correct answer is D .
• Question 1384:

  

  The compound above is an

  Options:
  A) alkanone
  B) alkanoate
  C) alkanal
  D) akanol
  Show Answer
  The correct answer is A .
• Question 1385: The pressure of 100cm³ of oxygen at 35^oC is 750mmHg. What will be the volume of gas if the pressure is reduced to 100mmHg without changing the temperature? Options:
  A) 650 cm³
  B) 850 cm³
  C) 580 cm³
  D) 750 cm³
  Show Answer
  The correct answer is D .
• Question 1386: In an electrochemical cell, polarization is caused by Options:
  A) Oxygen
  B) Hydrogen
  C) Tetraoxosulphate(IV) acid
  D) Chlorine
  Show Answer
  The correct answer is B .
• Question 1387:

  

  From the diagram above, find the amount of solute deposited when 200 cm³ of the solution is cooled from 55^oC to 40^oC

  Options:
  A) 0.10 mole
  B) 0.20mole
  C) 0.01 mole
  D) 0.02 mole
  Show Answer
  The correct answer is B .
• Question 1388: Sodium carbonate crystals on exposure to a dry atmosphere change to a white powder. This phenomenon is known as? Options:
  A) deliquescence
  B) hygroscopy
  C) oxidation
  D) efforescence
  E) sublimation
  Show Answer
  The correct answer is D .
• Question 1389:

  The part of the total energy of a system that accounts for the useful work done in a system is known as

  Options:
  A) Enthalpy change
  B) None of the above
  C) Gibb's free energy
  D) Entropy
  Show Answer
  The correct answer is C .
• Question 1390: Cathode rays causes an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the rays Options:
  A) are positively charged
  B) are negatively charged
  C) have mass
  D) travel in straight lines
  Show Answer
  The correct answer is D .