Worksheets3.1.7 Oxidation/reduction/redox equations
Total questions: 30
Worksheet time: 15mins
Which of these is not a redox reaction?
Cu2O + H2SO4 ⟶ CuSO4 + Cu + H2O
MgO + 2HCl ⟶ MgCl2 + H2O
SnCl2 + HgCl2 ⟶ Hg + SnCl4
MnO2 + 4HCl ⟶ MnCl2 + 2H2O + Cl2
Which species is not produced by a redox reaction between solid sodium iodide and concentrated sulfuric acid?
Na2SO4
H2S
S
SO2
V2O5 can be used as a catalyst in the Contact Process.
Which is a step in the Contact Process in which the vanadium is oxidised?
SO2 + V2O5 ⟶ SO3 + 2VO2
SO3 + 2VO2 ⟶ SO2 + V2O5
2VO2 + 0.5O2 ⟶ V2O5
V2O5 ⟶ 2VO2 + 0.5O2
Which of these shows nitrogen in its correct oxidation states in the compounds given?
A
B
C
D
Which of these is a redox reaction?
CaO + SiO2 ⟶ CaSiO3
H2SO4 + Na2O ⟶ Na2SO4 + H2O
NaBr + H2SO4 ⟶ NaHSO4 + HBr
Mg + S ⟶ MgS
Which of these species is the best reducing agent?
Cl2
Cl−
I2
I−
Which of the following shows chlorine in its correct oxidation states in the compounds shown?
A
B
C
D
Which substance is not produced in a redox reaction when solid sodium iodide reacts with concentrated sulfuric acid?
H2S
HI
SO2
I2
In which reaction is hydrogen acting as an oxidising agent?
Cl2 + H2 --> 2HCl
(CH3)2CO + H2 --> (CH3)2CHOH
N2 + 3H2 --> 2NH3
2Na + H2 --> 2NaH
In which reaction is the metal oxidised?
2Cu2+ + 4I– --> 2CuI + I2
[Fe(H2O)6]3+ + Cl– --> [Fe(H2O)5(Cl)]2+ + H2O
[CoCl4]2– + 6H2O --> [Co(H2O)6]2+ + 4Cl–
Mg + S --> MgS
Which species contains an element with an oxidation state of +4?
NO2+
ClO3−
H2SO3
PCl5
Refer to the unbalanced equation below when answering this question.
K2Cr2O7 + 3H2C2O4 + _H2SO4 → Cr2(SO4)3 + _H2O + 6CO2 + K2SO4
In the balanced equation the mole ratio for sulfuric acid to water is
1 : 4
1 : 2
4 : 7
4 : 9
Refer to the unbalanced equation below when answering this question.
K2Cr2O7 + 3H2C2O4 + _H2SO4 → Cr2(SO4)3 + _H2O + 6CO2 + K2SO4
What is the reducing agent in this reaction?
H+
C2O42−
K+
Cr2O72−
Which one of the following is the electron arrangement of the strongest reducing agent?
1s2 2s2 2p5
1s2 2s2 2p6 3s2
1s2 2s2 2p6 3s2 3p5
1s2 2s2 2p6 3s2 3p6 4s2
Which one of the following is not a redox reaction?
Br2 + SO2 + 2H2O → SO42- + 4H+ + 2Br−
SnCl2 + HgCl2 → Hg + SnCl4
Cu2O + H2SO4 → CuSO4 + Cu + H2O
2CrO42- + 2H+ → Cr2O72- + H2O
Refer to the following reaction
Which one of the following statements is correct?
This is a redox reaction.
The reaction is not feasible below 298 K
At equilibrium, the yield of hydrogen iodide is changed by increasing the pressure.
At equilibrium, the yield of hydrogen iodide increases as the temperature is increased.
Photochromic glass contains silver ions and copper ions. A simplified version of a redox equilibrium is shown below. In bright sunlight the high energy u.v. light causes silver atoms to form and the glass darkens. When the intensity of the light is reduced the reaction is reversed and the glass lightens.
Cu+(s) + Ag+(s) ⇌ Cu2+(s) + Ag(s)
clear glass dark glass
When the photochromic glass darkens
the Ag+ ion is acting as an electron donor.
the Cu+ ion is acting as a reducing agent.
the Ag+ ion is oxidised.
the Cu+ ion is reduced.
Which one of the following statements is not correct?
The first ionisation energy of iron is greater than its second ionisation energy.
The magnitude of the lattice enthalpy of magnesium oxide is greater than that of barium oxide.
The oxidation state of iron in [Fe(CN)6]3− is greater than the oxidation state of copper in [CuCl2]−
The boiling point of C3H8 is lower than that of CH3CH2OH
The vanadium does not have an oxidation state of +3 in
[V(H2O)6]3+
[V(C2O4)3]3−
[V(OH)3(H2O)3]
[VCl4]3−
In which one of the following reactions does hydrogen not act as a reducing agent?
H2 + Ca → CaH2
2H2 + O2 → 2H2O
H2 + CH2=CH2 → CH3CH3
2H2 + CH3COCH3 → CH3CH2CH3 + H2O
In which one of the following reactions is the role of the reagent stated correctly?
A
B
C
D
Which one of the following is a redox reaction?
2CrO43- + 2H+ → Cr2O72- + H2O
3Cl2 + 6OH− → 5Cl− + ClO3- + 3H2O
HNO3 + 2H2SO4 → NO2+ + H3O+ + 2HSO4-
CaCO3 + SiO2 → CaSiO3 + CO2
Which one of the following is not a redox reaction?
TiO2 + 2Cl2 + C → TiCl4 + CO2
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
MgO + 2HCl → MgCl2 + H2O
3MnO42- + 4H+ → 2MnO4- + MnO2 + 2H2O
In which one of the following reactions is H2O2 behaving as a reducing agent?
H2O2 + 2I− + 2H+ → I2 + 2H2O
H2O2 + 2[Co(NH3)6]2+ → 2[Co(NH3)6]3+ + 2OH−
5H2O2 + − 2MnO4- + 6H+ → 2Mn2+ + 8H2O + 5O2
3H2O2 + 2[Cr(OH)6]3− → 2CrO42- + 8H2O + 2OH−
In which one of the following reactions do two H ions and one electron have to be added to the left-hand side in order to balance the equation?
CH3CHO → CH3CH2OH
VO2+ → V3+ + H2O
NO3- → HNO2 + H2O
HOCl → 0.5Cl2 + H2O
Which equation does not involve the reduction of a transition metal compound?
Fe2O3 + 3CO → 2Fe + 3CO2
TiO2 + 2C + 2Cl2 → TiCl4 + 2CO
Cr2O3 + 2Al → 2Cr + Al2O3
TiCl4 + 4Na → Ti + 4NaCl
Which one of the following is the electronic configuration of the strongest reducing agent?
1s2 2s2 2p5
1s2 2s2 2p6 3s2
1s2 2s2 2p6 3s2 3p5
1s2 2s2 2p6 3s2 3p6 4s2
The compound lithium tetrahydridoaluminate(III), LiAlH4, is a useful reducing agent. It behaves in a similar fashion to NaBH4. Carbonyl compounds and carboxylic acids are reduced to alcohols. However, LiAlH4 also reduces water in a violent reaction so that it must be used in an organic solvent.
Which one of the following concerning the violent reaction between LiAlH4 and water is false?
A gas is produced.
The activation energy for the reaction is relatively high.
The reaction has a negative free-energy change.
Aqueous lithium ions are formed.
In which one of the following reactions does the metal species undergo reduction?
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
[Cu(H2O)6]2++ 4Cl− → [CuCl4]2− + 6H2O
CrO72- + 2OH− → 2CrO42- + H2O
TiO2 + 2C + 2Cl2 → TiCl4 + 2CO
Which one of the following contains the metal with the lowest oxidation state?
CrO2F2
[Cr2O7]2
[MnCl6]2−
[Mn(CN)6]3−
