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 371:

  From the graph above, it may be concluded that

  Options:
  A) AgNO${}_3$ is probably not soluble at 1100
  B) NaCl is insoluble in water
  C) Pb(NO${}_3$)${}_2$ is more soluble than KCIO${}_3$
  D) The solubility of KCIO${}_3$ exceeds that of NaCl at all temperature
  Show Answer
  The correct answer is C .
• Question 372: How many moles of oxygen molecules would be produced from the decomposition of 2.50 moles of potassium trioxochlorate (V)? Options:
  A) 2.50
  B) 3.50
  C) 3.75
  D) 7.50
  Show Answer
  The correct answer is C .
• Question 373: Which of the following types of reactions takes place between C₂H₄ and the halogens? Options:
  A) Substitution
  B) Polymerization
  C) Addition
  D) Saponification
  E) Oxidation
  Show Answer
  The correct answer is C .
• Question 374: Which of the following silver halides is readily soluble in ammonium hydroxide? Options:
  A) Agl
  B) AgBr
  C) AgCl
  D) AgF
  E) None of the above
  Show Answer
  The correct answer is C .
• Question 375: The atom of an element X is represented as ${}_z^{y}X$. The basic chemical properties of X depend on the value of Options:
  A) Y
  B) Z
  C) Y - Z
  D) Z - Y
  Show Answer
  The correct answer is B .
• Question 376: Three solutions contain carbonate, sulphate and sulphide ions respectively. One test that will identify just ONE of them completely is by addition to each of them of Options:
  A) barium chloride solution
  B) dilute hydrochloric acide
  C) lead nitrate solution
  D) calcium chloride solution
  E) sodium hydroxide solution
  Show Answer
  The correct answer is C .
• Question 377: In the laboratory preparation of chlorine from concentrated hydrochloric acid in the presence of potassuim tetraoxomanganate(VII) the produced is dried by passing it through Options:
  A) Concentrated tetraoxosulphate (VI) acid
  B) Anhydrous calcium chloride
  C) Calcium oxide
  D) Sodium hydroxide
  Show Answer
  The correct answer is A .
• Question 378: Crude petroleum pollutant usually seen on some Nigerian creeks and waterways can be dispersed or removed by Options:
  A) heating the affected parts in order to boil off the petroleum
  B) mechanically stirring to dissolve the petroleum in water
  C) pouring organic solvents to dissolve the petroleum
  D) spraying the water with stergents
  E) cooling to freeze out the petroleum
  Show Answer
  The correct answer is C .
• Question 379:

  I. Treatment of cancerII. Detection of leakages in water mainsIII. Detection of the ages of ancient toolsIV. Preparation of drugs

  Which combination of the above refers to the uses of radioactive isotopes?

  Options:
  A) I and III
  B) I and II
  C) I, II and III
  D) I, II, III and IV
  Show Answer
  The correct answer is C .
• Question 380:

  If the volume of a given mass of a gas at 0ºc is29.5cm${}^3$. What will be the volume of the gas at 15ºc, given that the pressure remains constant.

  Options:
  A) 31.6
  B) 62.2
  C) 32.7
  D) 31.1
  Show Answer
  The correct answer is D .