- 1. Consider the reaction represented by xIO3- + yI- + 6H+ --------> 2H₂O + 3₂ what are the values of x, y and z respectively?
A) 3, 1, 5
B) 5,5,3
C) 1, 5, 3
D) 5, 3, 1
- 2. Which of the compound can be used as a reducing agent in a reaction?
A) Na2SO3
B) KMnO4
C) K₂Cr₂O7
D) MnO2
- 3. Which statement best describes the process of oxidation?
A) addition of hydrogen
B) loss of oxygen
C) gain of electrons
D) loss of electrons
- 4. Determine the oxidation number of chromium in the compound K2Cr₂O7
A) +3
B) +2
C) +5
D) +6
- 5. X forms a trivalent cation while Y forms a divalent anion. The dissociation of a compound of X and Y can be written as
A) 3XY₂ → X3+ + Y2-
B) X2Y3 →2X3+ + 3Y2-
C) X3Y₂ → X3+ + Y2-
D) XY → X3+ + Y2-
- 6. What is the change in the oxidation number of Mn in the following reaction? MnO4-(aq) + 8H- (aq) + 5e- →Mn2+ + 4H2O (l)
A) +7 to +2
B) +8 to +2
C) -1 to +2
D) -4 to +2
- 7. What quantity of electrons (in mole) is lost when one mole of ion (II) ions is oxidised to ion (III) ions.
A) 2 moles
B) 3 moles
C) 4 moles
D) 1 mole
- 8. H2S (g) + Cl2(g) → 2HCl(g) + S(s)
The oxidising agent in the reaction above is - -
A) H₂S
B) Cl₂
C) HCl
D) S
- 9. In which of the following reactions has the oxidation number of nitrogen increases?
A) FeSO4 +NO(g) → Fe(NO)SO4(l)
B) 2NO(g) + Cl₂ (g) → 2NOCl (l)
C) 2NO(s) + Br2(l) → 2NOBr (l)
D) 2NO(g) + O2(g) → 2NO2 (g)
- 10. Cu₂S(s) +O2 (g) → 2Cu(s) +SO2(g)
What is the change in the oxidation number of copper in the reaction above?
A) +2 to +1
B) O to +2
C) +1 to O
D) O to +1
- 11. 3Cu2 + 8HNO3(aq) → 3Cu(NO3)_2(aq) + 4H2O(l) + 2NO(g)
In the equation above, copper is
.....
A) a base
B) an electron acceptor
C) a reducing agent
D) an oxidising agent
- 12. What is the value of x is the following equation? MnO4- + 4H+ + xe- → MnO2 + 2H₂O
A) 3
B) 4
C) 2
D) 7
- 13. Fe(s) + Cu2+ (aq) →Fe2+ + Cu(s)
in the reaction above, it can be inferred that
.......
A) Fe is the oxidising agent
B) Fe is reduced
C) Cu2+ loses electrons
D) Cu2+ is the oxidising agent.
- 14. The oxidation number of X in XO4³- is
........
A) +5
B) +3
C) +4
D) +2
- 15. The collective name for elements in the group seven is the ----------
A) halogens
B) alkali metals
C) alkalin-earth metals
D) inert gases
- 16. The position of an element on the periodic table is determined by........
A) the number of protons in its atom.
B) its relative atomic mass
C) its atomic radius
D) its density
- 17. The element with electronic configuration Is2 2s2 2p6 3s2 is
.....
A) a non-metal
B) a metal
C) an inert gas
D) a halogen
- 18. Lithium and sodium show similar chemical properties. Which of the following statements is not true about the two elements?
A) They have equal number of electrons in their outermost shells
B) Both exist in the +1 oxidation state in their compound
C) They belong to the same group in the periodic table
D) They are in the same period in the periodic table
- 19. The electronic configuration of elements X, Y and Z are as follows X- Is2 2s2 2p6 3s2 Y - Is² 2s² 2p6 3s2 3p¹ Z-Is² 2s²2p6 3s2 3p2 To which period do X, Y and Z belong?
A) 3
B) 1
C) 2
D) 4
- 20. Which of the following statements about the elements, Na, Mg, Al and Si is / are true?
I. They are all in period 3 of the periodic table II. Mg is more electropositive than Si
III. Electropositivity decreases from Na to Si IV. Si is the most electropositive element.
A) I, II, III and IV
B) I and IV only
C) I, II and III only
D) I only
- 21. The element with the electronic
configuration Is2 2s2 2p6 3s2 3p6 3d2 4s² is a/an
A) alkaline earth metal
B) transition metal
C) group II element
D) group IV element.
- 22. Li, Na, and K are in the same group in the periodic table because they have the same. ........
A) ionisation energy
B) atomic radius
C) number of valence electrons
D) electronic configuration
- 23. Use the diagram above to answer the following question. The letters indicating elements which exist as monoatomic gases are
......
A) X and R
B) T and W
C) R and S
D) P and Q
- 24. Use the diagram above to answer the following question. Which of the following pairs of letters denotes elements containing the same number of electrons in their outermost shells?
A) S and T
B) R and X
C) P and Q
D) T and P
- 25. Use the diagram above to answer the following question. What letter represents an element that undergoes covalent bonding?
A) S
B) R
C) Q
D) T
- 26. Use the diagram above to answer the following question. Which letter represents a halogen?
A) R
B) P
C) S
D) X
- 27. What is the most probable group of an element which is a soft, silvery-white solid and reacts violently with water?
A) Group 1
B) Group 6
C) Group 4
D) Group 7
- 28. Which of the following electronic configurations indicates an atom with the highest ionisation energy?
A) 2,8,8,7
B) 2,8,8,2
C) 2,8,8,1
D) 2, 8, 7
- 29. P, Q, R and S are metals in the same group in the periodic table but in periods 3,4,5 and 6 respectively. Which of them loses electrons least readily?
A) P
B) Q
C) R
D) S
- 30. Which of the following substances is a non-electrolyte?
A) H2SO4
B) C6H12O6
C) CH3COOH
D) NH4Cl
- 31. Zinc will displace copper ions from
solution but silver will not because in the electrochemical series
.....
A) silver is higher than zinc and copper
B) silver is higher than copper but lower than zinc
C) zinc is lower than copper and silver
D) zinc is higher than copper whereas silver is lower than copper
- 32. If 20cm³ of H₂ was liberated at the cathode during the electrolysis of dilute tetraoxosulphate (VI) acid, what volume of O₂ would be liberated at the anode
.....
A) 20cm³
B) 40cm³
C) 5cm³
D) 10cm³
- 33. The energy conversion in an electrolytic cell is
A) chemical to mechanical
B) electrical to mechanical
C) electrical to chemical
D) chemical to electrical
- 34. In the diagram above X and Y are known as -
A) carbon
B) conductors
C) electrodes
D) metal plates
- 35. Oxidation takes place at the anode during electrolysis because the anode
A) is deficient in electrons
B) has attraction for positive ions.
C) has excess electrons
D) is deficient in protons
- 36. The product at the cathode when copper(II) tetraoxosulphate (VI) solution is electrolysed using copper electrodes is
A) copper
B) hydrogen
C) sulphur
D) oxygen
- 37. Which of the following ions will migrate to the cathode during electrolysis?
A) Tetraoxsulphate (VI) ions
B) Chloride ions
C) Zinc ions
D) Sulphide ions
- 38. The common feature of reactions at the anode is that
...
A) oxidation is involved
B) the electrode dissolves
C) ions are reduced
D) electrons are consumed
- 39. A metal M displaces zinc from zinc chloride solution. This shows that ....
A) M is more electropositive than zinc.
B) M is more electronegative than zinc
C) zinc is above hydrogen in the series
D) electrons flow from zinc to M
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