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 1171:

  Electrons enter into orbitals in order of increasing energy as exemplified by?

  Options:
  A) 1S${}^2$2S${}^2$2PX${}^2$2py${}^2$2pz${}^0$3s${}^0$
  B) 1S${}^2$2S${}^2$2PX${}^2$2py${}^1$2pz${}^1$3s${}^0$
  C) 1S${}^2$2S${}^2$2PX${}^1$2py${}^1$2pz${}^1$3s${}^1$
  D) 1S${}^2$2S${}^2$2PX${}^2$2py${}^2$2pz${}^0$3s${}^1$
  Show Answer
  The correct answer is B .
• Question 1172:

  CH_4(g) + CI_2(g) $\to$ CH₂CI_(s) + HCI_g

  The major factor that influences the rate of the reaction above is

  Options:
  A) Concentration
  B) Catalyst
  C) Temperature
  D) Light
  Show Answer
  The correct answer is D .
• Question 1173: A fixed mass of gas has a volume of 92cm₃ at 3 ^oC. When will be its volume at 18 ^oC if the pressure remains constant Options:
  A) 15.3cm³
  B) 87.3cm³
  C) 552.0cm³
  D) 97.0cm³
  Show Answer
  The correct answer is D .
• Question 1174:

  A few drop of conc HCL are added to about 10cm${}^3$ of a solution of PH 3.4. The PH of the resulting mixture is?

  Options:
  A) less than 3.4
  B) greater than 3.4
  C) unaltered
  D) the same as that of the pure water
  Show Answer
  The correct answer is A .
• Question 1175:

  Mg²⁺_(aq) + 2e^->_(aq) → Mg_(s)E°_(volts) = 2.370

  Zn²⁺_(aq) + 2e^->_(aq) → Zn_(s)E°_(volts) = -0.763

  Cds²⁺_(aq) + 2e^->_(aq) → Cd_(s)E°_(volts) = 0.403

  Cu²⁺_(aq) + 2e^->_(aq) → Cu_(s)E°_(volts) = 0.340

  In the electrochemical series above, the strongest reducing agents is?

  Options:
  A) Cu _(s)
  B) Cd_(s)
  C) Znsub>(s)
  D) Mg_(s)
  Show Answer
  The correct answer is D .
• Question 1176: The IUPAC names of the compounds CH₃COOH and CH₂=CH₂ are respectively; Options:
  A) acetic acid and ethane
  B) ethanoic acid and ethene
  C) methanoic acid and ethylene
  D) ethanol and ethene
  E) acetic acid and ethylene
  Show Answer
  The correct answer is B .
• Question 1177:

  The general formula for the Alkanals is?

  Options:
  A) R${}_2$CO
  B) RCHO
  C) ROH
  D) RCOOR
  Show Answer
  The correct answer is B .
• Question 1178: A mixture contains 20cm³ of hydrogen, 35cm³ of oxygen, 15cm³ of carbon monoxide and 10cm³ of nitrogen at S.T.P. Which of the following gives the mole fraction of hydrogen in this mixture? Options:
  A) 0.02
  B) 0.16
  C) 0.20
  D) 0.25
  E) 20
  Show Answer
  The correct answer is D .
• Question 1179: The process that occurs when two equivalent forms of a compound are in equilibrium is Options:
  A) Isotopy
  B) Resonance
  C) Isomerism
  D) Reforming
  Show Answer
  The correct answer is B .
• Question 1180: What is the pH of 0.001 mol dm4 solution of sodium hydroxide? Options:
  A) 14
  B) 13
  C) 12
  D) 11
  E) 10
  Show Answer
  The correct answer is D .