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