Worksheets[EXP SCI CHEM] 10 Redox
Total questions: 16
Worksheet time: 11mins
Choose all the statements which contain correct definitions of reduction.
loss of oxygen
loss of hydrogen
loss of electrons
decrease in oxidation state
Reduction is the ___________ of electrons.
(Hint: LEO GER)
loss
gain
sharing
transfer
Oxidation is the _________ of electrons.
(Hint: LEO GER)
loss
gain
sharing
transfer
Is calcium oxidised or reduced in the following reaction?
2CaO--> 2Ca + O2
Oxidised
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
Both reduced and oxidised
Oxidised
Which of the following represents reduction?
(Hint: Recall gain/loss of oxygen/hydrogen/electrons
The half equation is shown for Mg forming Mg2+.
Mg → Mg2+ + 2e–
Which statement is true?
Mg gains 2 electrons and is reduced
Mg2+ loses 2 electrons and is oxidised
Mg loses 2 electron is is reduced
Mg loses 2 electrons and is oxidised
Which of the following half reactions correctly represents a reduction half equation?
(Hint: reduction should be a gain of electrons)
Fe → Fe2+ + 2e-
2O2- →O2 + 4e-
What substance is oxidised in the following reaction?
4Fe + 3O2 --> 2Fe2O3
Iodine
The ionic equation shows the reaction between zinc (Zn) and hydrochloric acid.
Zn + 2H+ --> Zn2+ + H2
What change takes place in the zinc?
It gains electrons
It is oxidised
It is reduced
It gains hydrogen
Which one of the following conversions is an example of reduction?
(Note: the equations shown are not balanced)
Copper(II) oxide to copper(II) sulfate
CuO --> CuSO4
Copper(II) oxide to copper
CuO --> Cu
Hydrochloric acid to chlorine
HCl --> Cl2
Lead(II) nitrate to lead (II)chloride
Pb(NO3)2 --> PbCl2
In the reaction, Fe2O3(s) + 3CO(g) → 2Fe(l) + 3CO2(g)
carbon monoxide is reduced
carbon monoxide gains oxygen
iron(III) oxide is oxidised
iron(III) oxide gains electrons
Select all the equations whereby the underlined substances has been oxidised.
carbon dioxide + carbon -> carbon monoxide
CO2 + C --> 2CO
iron (II) oxide + aluminium -> aluminium oxide + iron
3FeO + 2Al --> Al2O3 + 3Fe
copper (II) oxide + ammonia -> copper + nitrogen + water
3CuO + 2NH3 --> 3Cu + N2 + 3H2O
hydrogen + oxygen -> water
2H2 + O2 --> 2H2O
AgNO3 + NaCl --> AgCl + NaNO3
Which substance(s) is/are oxidised?
silver nitrate
sodium chloride
both silver nitrate and sodium chlroide
neither are oxidised
The ionic equation shows the reaction between zinc (Zn) and hydrochloric acid.
Zn + 2H+ -> Zn2+ + H2
What change takes place in the zinc?
It gains electrons
Its oxidation state increases
It is reduced
It gains hydrogen
