Chemistry Past Questions And Answers

Note: You Can Select Post UTME Schools Name Below The Exam Year.
891

A balanced chemical equation obeys the law of?

  • A. conservation of mass
  • B. difinite proportions
  • C. multiple proportions
  • D. conservation of energy
View Discussion (0)JAMB 1993
892

According to the Kinetic Theory an increase in temperature causes the kinetic energy of particles to

  • A) decrease
  • B) increase
  • C) be zero
  • D) remain constant
View Discussion (0)JAMB 2018
893

(a) (i) Define the term fermentation

(ii) Name the catalyst that can be used for this process

(b) Name two factors which determine the choice of an indicator for an acid-base titration

(c) Consider the following reaction equation: Fe + H\(_2\)SO\(_4\) \(\to\) FeSO\(_4\) + H\(_2\). Calculate the mass of unreacted iron when 5.0g of iron reacts with 10cm\(^3\) of 1.0 moldm\(^3\) H\(_2\)SO\(_4\), [Fe = 56.0]

(d) Name one:

(i) Heavy chemical used in electrolytic cells

(ii) Fine chemical used in textile industries

(e) Explain briefly how a catalyst increases the rate of a chemical reaction.

(f) (i) Write the chemical formula for the product formed when ethanoic acid reacts with ammonia

(ii) Give the name of the product formed in (f)(i)

(g) List three properties of aluminum that makes it suitable for the manufacture of drinks cans

(h) State two industrial uses of alkylalkanoates

(i) Name two steps involved in the crystallization of a salt from its solution

(j) List two effects of global warming

View Discussion (0)WAEC 2018 THEORY
894

The pH of a solution obtained by mixing 100cm3. 0.1M HCl solution with 100cm3 of a 0.2M solution of NaOH is

  • A) 1.3
  • B) 7.0
  • C) 9.7
  • D) 1.7
View Discussion (0)POST UTME FUTO
895

(a) Name one product of destructive distillation of coal that is (i) solid (ii) liquid; (iii) gas.

(b) (i) What is the major component of synthetic gas? (ii) Give one reason why synthetic gas is not a major source of air pollution.

(c) (i) Write a balanced chemical equation for the complete combustion of carbon. (ii) State two: I. physical; II. chemical properties of the product in (c)(i).

(d) (i) Name two allotropes of carbon that are I. crystalline, II. amorphous. (ii) State one use of each of the allotropes named in (d)(i).

(e) (i) By means of balanced chemical equations only, outline the process of manufacture of H\(_2\)SO\(_4\), by contact process.

(ii) State the function of H\(_2\)SO\(_4\) in each of the following reaction equations:

I. C\(_2\)H\(_5\)OH\(_{2(l)}\) \(\to\) C\(_2\)H\(_{4(g)}\);

II. Pb(NO\(_{3(g)}\) + H\(_2\)SO\(_{4(g)}\) —> PbSO\(_{4(s)}\) + 2HNO\(_{3(aq)}\)

View Discussion (0)WAEC 2010 THEORY
896

Which of the following statements about the solubility of a salt is correct?

  • A. A salt whose solubility increases with temperature would not crystallize easily on cooling
  • B. A salt whose solubility is independent of temperature would normally crystallize out on cooling
  • C. Crystallization would be efficient in separating out a salt whose solubility increases considerably with temperature
  • D. Solubility of a solid does not affect its crystallization
View Discussion (0)WAEC 2020 OBJ
897

The gas which causes global warming is?

  • A. O2
  • B. CO2
  • C. N2
  • D. He
View Discussion (0)JAMB 2021
898

Alloys are often used in preference to pure metals because?

  • A. metals are too hard
  • B. merals are ductile
  • C. metallic properties are improve in alloys
  • D. alloys are a mixture of metals
View Discussion (0)JAMB 1998
899

The following alloys contain copper except

  • A. magnalium
  • B. duralumn
  • C. bronze
  • D. brass
View Discussion (0)WAEC 1990 OBJ
900

A dye is suspected to have contaminated a lollipop. Which of the following is the best method by which the contaminant may be isolated?

  • A. Fractional distillational
  • B. Recrystallization
  • C. Filtration
  • D. Paper chromatography
View Discussion (0)WAEC 1992 OBJ