Redox Review Questions
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1)
Redox reactions are reactions in which ____________ are transferred.2) An overall redox reaction can be divided into ________ reactions. One of these reactions involves oxidation (the ______________), while the other reaction involves reduction (the ___________________).
3) Redox reactions can be identified by comparing the _________________ of the reactants and the products. In a redox reaction these ___________________ will change, while in a non-redox reaction the oxidation states will __________________.
4) ______________ replacement reactions are always redox reactions, while _____________ replacement reactions are never redox reactions.
Identify the oxidation states of the following elements:
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5) H in H2O |
_________ |
10) |
Na in Na metal |
_________ |
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6) O in CO2 |
_________ |
11) |
S in H2S |
_________ |
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7) N in N2 |
_________ |
12) |
S in H2SO4 |
_________ |
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8) N in NH3 |
_________ |
13) |
S in H2SO3 |
_________ |
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9) N in HNO3 |
_________ |
14) |
Cr in K2CrO4 |
_________ |
Identify the following reactions as redox or non-redox by determining the oxidation states of the products and reactants:
15) 2H2 + O2 --> 2H20
16) 2 Na + Cl2 --> 2 NaCl
17) NaOH + HCl --> NaOH + H2O
18) Zn + 2 HCL --> ZnCl2 + H2
19) CaCO3 --> CaO + CO2
20) HCl + AgNO3 --> AgCl + HNO3
Write half reactions for each of the following redox reactions:
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21) |
Na + Ag+ --> Na+ + Ago |
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Oxid. |
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Red. |
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22) |
Cu2+ + 2Ago --> Cuo + Ag+ |
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Oxid. |
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Red. |
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23) |
Cu2+ + Zno ---> Cuo + Zn2+ |
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Oxid. |
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Red. |
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25 ) |
2 Fe+3 + 3 Zn --> 2 Feo + 3 Zn2+ |
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Oxid. |
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Red. |
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26) |
Write the 1/2 reactions and then use them to adjust the coefficients to balance the following equation: ____ Fe3+ + __ Alo --> ____ Fe2+ +____ Al3+ |
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Oxid. |
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Red. |
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27) |
Write the 1/2 reactions and then use them to adjust the coefficients to balance the following equation: ____ Fe3+ + __ Alo --> ____ Fe0+ +____ Al3+ |
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Oxid. |
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Red. |
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28) The reducing agent is the substance that is _______________, while the oxidizing agent is the substance that is _______________.
For the following reactions, identify the reducing agent and the oxidizing agent.
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Reaction |
Reducing Agent |
Oxidizing Agent |
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29) 2 Na + Cl2 --> 2 NaCl |
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30) Mg + 2 HCl --> MgCl2 + H2 |
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31) 2 H2 + O2 --> 2 H2O |
32) An electrochemical cell that requires energy to occur is classified as an _______________. A common application of this concept is in the _______________used in making some jewelry.
33) Batteries are examples of electrochemical cells that can be used to produce energy. These cells are called _______________or _______________ cells.
34) In any electrochemical cell, reduction always occurs at the _______________, while oxidation always occurs at the _______________.