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 1311: The pH of a solution obtained by mixing 100cm³ of a 0.2M solution of NaOH is? Options:
  A) 1.3
  B) 7.0
  C) 9.7
  D) 12.7
  Show Answer
  The correct answer is D .
• Question 1312:

  

  Use the figure above to answer this question. Which of the following is NOT a monomer?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 1313: An element, E, has the electronic configuration 1s²2s²2p⁶3s²p³. The reaction of E with a halogen X can give? Options:
  A) EX₃ and EX₅
  B) EX₃ only
  C) EX₅ only
  D) EX₂ and EX₃
  Show Answer
  The correct answer is A .
• Question 1314: Chlorine consisting of two isotopes of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotopes of mass number 37 Options:
  A) 20
  B) 25
  C) 60
  D) 75
  Show Answer
  The correct answer is B .
• Question 1315:

  The solubility in mol dm^-3 of 20g of CuSO₄ dissolved in 100g of water at 180^o is

  [Cu = 64, S = 32, O =16]

  Options:
  A) 0.13
  B) 0.25
  C) 1.25
  D) 2.00
  Show Answer
  The correct answer is C .
• Question 1316:

  The knowledge of half-life can be used to

  Options:
  A) Create an element
  B) Detect an element
  C) Split an element
  D) Irradiate an element
  Show Answer
  The correct answer is C .
• Question 1317: To a solution of an unknown compound, a little dilute tetraoxosulphate (VI) acid was added with some freshly prepared iron (II) tetraoxosulphate (VI) solution. The brown ring observed after the addition of a stream of concentrated tetraoxosulphate (VI) acid confirmed the presence of Options:
  A) CO^-
  B) Cl^-
  C) SO^-
  D) NO
  Show Answer
  The correct answer is D .
• Question 1318:

  The maximum electron in N shell is?

  Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is D .
• Question 1319: Sodium hydroxide (NaOH) pellets are Options:
  A) deliquescent
  B) hygroscopic
  C) efflorescent
  D) hydrated
  E) fluorescent
  Show Answer
  The correct answer is A .
• Question 1320: The electronic configuration of an elements is 1s²2s²2p⁶3s²3p³. How many unpaired electrons are there in the element? Options:
  A) 5
  B) 4
  C) 3
  D) 2
  Show Answer
  The correct answer is C .