Chemistry Chapter 9 Entry Test MCQs
26. The oxidation numbers of P in P4, PH3 and NaH2PO2, respectively, are
a. 0, +3, –1
b. 0, –3, +1
c. 0, +3, +1
d. 0, –3, –1
27. In Ca(OCl)Cl, the oxidation state of Cl is
a. – 2, +1, 0
b. Zero
c. + 1, -1
d. +2, -1
28. In which of the following the oxidation number of oxygen has been arranged in increasing order?
a. BaO2 < KO2 < O3 < OF2
b. OF 2 < O3 < KO3 2< BaO2
c. KO2 < OF2 < O3 < BaO2
d. OF2 < KO2 < BaO2 < O3
29. Which of the following elements in glucose has zero oxidation state?
a. O
b. C
c. H
d. All
30. Which of the following aqueous solution will conduct an electric current quite well?
a. Sugar
b. Glycerol
c. Pure water
d. HCl
31. Which is responsible for electrical conduction of molten sodium chloride:
a. Free ions
b. Free electrons
c. Atoms of sodium and chlorine
d. Free molecules
32. Which one of the following can have positive and negative oxidation state in various compound?
a. Iodine
b. Fluorine
c. Helium
d. Sodium
33. In which of the following compounds, nitrogen exhibits highest oxidation state?
a. N2H4
b. N2O
c. N2O3
d. NH2OH
34. Oxidation state of ‘Mn’ in KMnO4, K2MnO4, MnO2 and MnSO4 is in the order
a. + 6, +7, +2, +4
b. + 7, +6, +2, +4
c. + 4, +6, +7, +2
d. + 7, +6, +4, +2
35. The oxidation states of sulphur in the anions SO3 2 –, S2O4 2- and S2O6 2- follow the order:
a. S2O4 2- < S2O6 2- < SO3 -2
b. SO3 2- < S2O4 2- < S2O6 -2
c. S2O6 2- < S2O4 2- < SO3 2-
d. S2O4 2- < SO3 2- < S2O6 2-
Balancing Equations
36. In the reaction, 3Br2 + 6CO3 2- + 3H2O → 5Br– + BrO3 + 6HCO3–
a. bromine is reduced and water is oxidized
b. is reduced bromine is oxidized and carbonate
c. bromine is both reduced and oxidized.
d. bromine is neither reduced nor oxidized
37. When KMnO4 acts as an oxidizing agent and ultimately forms MnO4 2- MnO2, Mn2O3 and Mn2+ then the number of electrons transferred in each case respectively is
a. 1, 3, 4, 5
b. 1, 5, 3, 7
c. 4, 3, 1, 5
d. 3, 5, 7, 1
38. The number of moles of KMnO4 reduced by one mole of KI in alkaline medium is
a. 5
b. 2
c. 6
d. 1
39. One mole of acidified K2Cr2O7 on reaction with excess KI will liberate …… moles of I2.
a. 3
b. 1
c. 5
d. 2
40. KMnO4 is a strong oxidizing agent in acid medium. To provide acid medium H2SO4 is used instead of HCI. This is because
a. Rate is faster in the presence of H2SO4
b. Only H2SO4 is completely ionized.
c. HCl is oxidized by KMnO4 to Cl2
d. H2SO4 is a dibasic acid
41. How many electrons are required to balance the following half reaction 2H2O + MnO4 –1 → MnO2 + 4OH–
a. 6e– on the left
b. 6e– on the right
c. 3 e– on the left
d. 3 e– on the right
42. The stoichiometric numbers of species from left to right in the chemical equation when balanced respectively are NaOH + Br2 NaBrO3 + NaBr + H2O
a. 2, 4, 3, 1, 2
b. 3, 4, 3, 1, 2
c. 6, 3, 1, 5, 3
d. 1, 2, 1, 1, 2
43. In the balanced chemical reaction, lo3– + al + bH+ → ch2o + a,b,c, and d respectively corresponds to:
a. 3, 6, 5, 3
b. 4, 5, 6, 3
c. 5, 6, 3, 3
d. 5, 6, 2, 3
Electrochemical Cells
44. The aqueous solution of which of the following compounds is the best conductor of electric current?
a. Ammonia
b. Acetic acid,
c. Fructose
d. Hydrochloric acid
45. Metal that deposits at cathode when aqueous solution of its salt is electrolysed
a. Zn
b. Na
c. Sn
d. Cu
46. If electricity is passed through CuSO4 solution by using Pt electrode, then which of the following possible change occurs
a. Colour of the solution becomes fade
b. H2 is deposited at cathode
c. Cu is deposited at anode
d. All are possible
47. The electrolysis of concentrated brine solution produces all of the following except:
a. Chlorine
b. Hydrogen
c. Caustic soda
d. Oxygen
48. For the electrochemical cell Mg/MgCl2(1M) || Fe2(SO4)3(1M)/Fe, the number of electrons involved in the balanced equation are
a. 3
b. 2
c. 6
d. 4
49. When 5 moles of electrons are passed through a molten aluminium salt, what is the maximum mass of aluminium deposited at cathode:
a. 27g
b. 5.4g
c. 45 g
d. 16.2g
50. In aqueous solution, strong electrolytes
a. Form polymers
b. Are partially ionized
c. Ionize almost completely
d. Do not ionize