Target: 10 Questions in 10 minutes

An IB Chemistry data booklet is helpful
1. Which of the following statements is false?
  • A.   Loss of electrons leads to oxidation.
  • B.   During oxidation the oxidation number increases.
  • C.   An oxidizing agent gets reduced in a redox reaction.
  • D.   If an atom gains electrons, its oxidation state increases.
2. When the following half-equation is balanced, what is the sum of all the coefficients for the oxidation of one mole of methanol?

.....CH3OH  +  .....H2O   →  .....HCOOH   +   .....H+   +  .....e-

 methanol 3d balls
  • A.   4
  • B.   7
  • C.   8
  • D.   11

3. In which of the following changes is a reducing agent required?

  • A.   IO3-  → I2
  • B.   Cl2    → ClO-
  • C.   SO2    → H2SO4
  • D.   NH3    → NO2-
4. Which of the following reactions is not a redox reaction?
  • A.   5Br- + BrO3- + 6H+  → 3Br2 + 3H2O
  • B.   HPO42- + H2O  → H2PO4- + OH-
  • C.   2CuSO4 + 4KI  → 2CuI + I2 + 2K2SO4
  • D.   Zn + 2AgNO3  → Zn(NO3)2 + 2Ag

5. When the following half-equation is balanced using the simplest whole number coefficient, how many electrons are required?

.....FeO42-  +   .....H+   +  .....e−  → .....Fe3+   +   .....H2O
  • A.   1
  • B.   2
  • C.   3
  • D.   4
6. For the reaction between K2MnO4 and an acid:

3MnO42-(aq) + 4H+(aq)  → 2MnO4-(aq) + MnO2 (s) + 2H2O(l)

which of the following statements is false?

  • A.   The IUPAC name for K2MnO4 is potassium manganate(VI)
  • B.   The species oxidised in the reaction is MnO42- (aq).
  • C.   The order of species in the order of increasing oxidation state for Mn is MnO2, MnO4- and MnO42-
  • D.   The reducing agent in this reaction is MnO42-

7. To find the concentration of Cu2+ in a 100 cm3 of copper(II) sulphate solution, 25 cm3 of the solution is pipetted into a conical flask and mixed with excess potassium iodide KI (equation 1).

The iodine formed is titrated with 0.05 mol dm-3 sodium thiosulfate Na2S2O3 solution (equation 2) and 40 cm3 of sodium thiosulfate is used for this titration.

 
2Cu2+(aq) + 4I-(aq)  → 2CuI(s) + I2(aq) Equation 1
I2(aq) + 2S2O32-(aq)  → 2I-(aq) + S4O62- (aq) Equation 2

What was the concentration of Cu2+ in the original copper(II) sulfate solution?

  • A.   0.04 mol dm-3
  • B.   0.08 mol dm-3
  • C.   0.10 mol dm-3
  • D.   0.16 mol dm-3
8. Calculate the volume of hydrogen gas required to fully reduce 500 cm3 of butane-1,3-diene at standard temperature and pressure.
  • A.   44.1 cm3
  • B.   454 cm3
  • C.   500 cm3
  • D.   1000 cm3
9. Which products cannot be formed through the oxidation of propan-1-ol?
  • A. Propanal
  • B. Carbon dioxide
  • C. Propanone
  • D. Propanoic acid
10 Which compound can be oxidized to form a ketone using acidified potassium manganate(VII)?
  • A.   CH3CH2CH2OH
  • B.   CH2=CHCH3
  • C.   CH2BrCH2CH3
  • D.   CH3CH(OH)CH3