Any chemical reaction in which the oxidation number of a participating chemical species changes is referred to as an oxidation-reduction reaction. The term refers to a wide range of processes. Many oxidation-reduction reactions are as common and familiar as fire, metal rusting and dissolution, fruit browning, and basic life functions like respiration and photosynthesis.
Download Class 11 Chemistry Worksheet on Chapter 8 Redox Reactions Set 5 PDF.
CBSE Class 11 Chemistry Chapter 8 Redox Reactions – Set 5
Q-1: A smuggler could not transport the gold by depositing iron on its surface because
a) Gold is denser
b) Iron rusts.
c) The electrode potential of gold is greater than that of iron.
d) Gold’s electrode potential is lower than iron.
Q-2: What is the best description of bromine’s behaviour in the reaction given below?
H2O + Br2 → HOBr + HBr
a) Both oxidised and reduced
b) Proton donor
c) Proton acceptor
d) Reduced only
Q-3: A compound is made up of atoms from three different elements: X, Y and Z. If X’s oxidation number is +2, Y’s is +5, and Z’s is -2, the compound’s possible formula is
a) X3(YZ4)2
b) X4(YZ3)2
c) X3(Y4Z)2
d) XYZ2
Q-4: The oxidation state of chromium in [Cr(PPh3)3(CO)3] is
a) +3
b) Zero
c) +8
d) None of the above
Q-5: A standard hydrogen electrode has no electrode potential because
a) Hydrogen is the easiest element to oxidise.
b) This electrode potential is assumed to be zero.
c) Hydrogen atoms only have one electron.
d) Hydrogen is the lightest element.
Q-6: Which of the following statements about the electrochemical Daniell cell is correct?
a) Electrons move from copper to zinc electrodes.
b) Electric current flows from the zinc electrode to the copper electrode.
c) Cations move towards the copper electrode.
d) Cations move toward the zinc electrode.
Q-7: I2 and Br2 are added to a solution containing Br– and I– ions. What reaction will occur if,
I2 + 2e– → 2I– ; Eo= +0.54 V and Br2 + 2e– → 2Br– ; Eo= +1.09 V ?
Q-8: Arrange X, Y, Z, E, F, and H in order of increasing electrode potential in the electrochemical series if
X + H2SO4 → XSO4 + H2
XCl2 + Z → ZCl2 + X
FCl2 + Z → No reaction
2YCl + E → ECl2 + 2Y
H2SO4 + E → No reaction
Q-9: Provide stock notation for the following compounds.
a) Cu2Cl2
b) Na2CrO4
c) Mn2O7
d) V2O5
e) Cr2O3
Q-10: Find out the ratio of the equivalent weight of H2C2O4.2H2O as acid and its equivalent weight as a reductant.
Q-11: 12.53 cm3 of 0.051 M SeO2 reacts exactly with 25.5 cm3 of 0.1 M CrSO4, which is oxidised to Cr2(SO4)3. To what oxidation state is the selenium converted during the reaction?
Q-12: Sulphite (SO32-) ions are present in some acid rainwater. What is the amount of SO32-ions per litre in rainwater if 25.0 cm3 of this water sample requires 35.0 cm3 of 0.02 M KMnO4 solution for titration?
Q-13: What is the oxidation number of metals in
i) [Fe(CN)6]4-
ii) MnO4–
Q-14: Give the three points of difference between oxidation number and valency.
Q-15: Select the reducing agent which can reduce the following ions to their metallic state.
a) Ag+(aq)
b) Ni2+(aq)
Q-16: How can you identify the presence of iodide and bromide ions in the solution?
Q-17: Define cathode and anode.
Q-18: Write a balanced ionic equation for the reaction of K2Cr2O7, potassium dichromate (VI), and sodium sulphite Na2SO3 in an acidic medium to produce chromium (III) ion and sulphate ion.
Q-19: Calculate the average oxidation number of C in CH3COOH compound.
Q-20: Why is electrode potential also called the potential for half cell?
Download the PDF to access answers to the Chemistry Worksheet for Class 11 Chemistry Chapter 8 Redox Reactions Set – 5.
