Past Questions And Answers
(a) (i) State three characteristic properties of transition metals.
(ii) What is the oxidation state of manganese In each of the following species? (1) MnCl\(_2\) (II) MnO\(_2\) (III) MnO\(_4^{-}\)
(iii) Explain why manganese conducts electricity in the solid state but manganese chloride conducts only when molten or in solution.
(b)(i) The collision theory suggests that for two particles to react, they must collide. What two factors determine whether or not the collision would lead to formation of products?
(ii) Use an energy profile diagram to illustrate what is meant by the enthalpy change (\(\Delta\)H) and the activation energy (E\(_A\)) of a reaction.
(c) When few drops of aqueous KSCN are added to a solution of iron (III) salt the following equilibrium is set up:
Fe\(^{3}_{(aq)}\) + 3SCN\(^{-}_{(aq)}\) \(\rightleftharpoons\) Fe(SCN)\(_{3(aq)}\)
yellow colourless deep red
The equilibrium mixture has a pale red colour.
(i) Explain what would happen if more KSCN\(_{(aq)}\) were added to the equilibrium mixture.
(ii) Which of the ions in the equilibrium mixture forms an insoluble hydroxide with NaOH\(_{(aq)}\)? Write an equation for the reaction
(iii) State two changes observed on adding NaOH\(_{(aq)}\) to the equilibrium mixture.
View Discussion (0)WAEC 2003 THEORYThe pattern of end rhymes in a poem is called
- A. internal rhyme
- B. rhyme scheme
- C. rhythm
- D. scansion
A body of mass m, has a specific heat capacity s, and a heat capacity c. If the temperature of the body changes by \(\theta^oC\), Which of the following equation is correct?
- A. ms\(\theta\) = mv-1
- B. ms = C
- C. ms = s\(\theta\)
- D. ms = c\(\theta\)
In genetic counseling, a man with hemoglobin formation HbA HbS is most preferred to marry a woman of?
- A. HbA HbA
- B. HbC HbH
- C. HbM HbF
- D. HbS HbS
The use of a three-column cash book is determine by?
- A. cash discounts
- B. trade discounts
- C. cash transactions
- D. bank transactions
Find the value of p for which \(x^{2} - x + p\) becomes a perfect square.
- A. \(-\frac{1}{2}\)
- B. \(\frac{1}{4}\)
- C. \(\frac{1}{2}\)
- D. \(1\)
Enumerate four rights of children in Islam and explain how they could be abused.
View Discussion (0)WAEC 2020 THEORYThe introduction of division of labour in a firm will lead to?
- A. a fall in output
- B. a decline in the efficiency of labour
- C. an increase output
- D. the separation of ownership from management
One of the following is not among the ?I am sayings of Jesus
- A) I am the bread of life
- B) I am the gale of life
- C) I am the good shepherd
- D) I am the way
The principle of column chromatography is based on the ability of the constituents to
- A) move at different speeds in the column
- B) dissolve in each other in the column
- C) react with the solvent in the column
- D) react with each other in the column

