Download Test Objectives for Unit 11: Oxidation/Reduction

Honors Chemistry
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Date: _________
Test Objectives for Unit 15: Oxidation/Reduction
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Define oxidation.
Define reduction.
Assign oxidation numbers to each element in a compound or a polyatomic ion.
o Know the rules for assigning oxidation numbers.
Explain what an oxidation-reduction (redox) reaction is.
Identify whether a chemical equation is a redox reaction or not.
o (Hint: what kind of reaction is always redox?)
Determine what is being oxidized and what is being reduced in a redox reaction.
Memorize “An Ox Ate a Red Cat” and “Oil Rig.”
Identify the oxidizing agent and the reducing agent in a redox reaction.
Write correct equations for the oxidation half-reaction and the reduction half-reaction in a
redox reaction.
Balance a redox equation, by balancing electrons lost with electrons gained.
Use Table J to predict whether a particular redox reaction will occur or not.
Use a table of standard electrode potentials to determine whether a particular redox reaction
will occur or not.
Relate chemical activity to oxidizing and reducing strength.
Explain the concept of disproportionation.
In an electrochemical (or galvanic or voltaic) cell, a spontaneous chemical reaction is used
to produce electricity. (spontaneous reaction → electricity) This is an exothermic process.
What type of energy is produced?
Identify the components of an electrochemical cell and describe their function. (half-cell,
salt bridge, wire, electrode, anode where oxidation occurs, cathode where reduction
occurs) Use Table J to determine which electrode is the anode and which electrode is the
cathode. (The higher metal donates electrons, so it’s the anode. The lower electrode is the
site of reduction and will be the cathode.) Assign + and – signs to the electrodes. Opposites
attract – the polarity is determined by the direction of electron flow.
Describe what happens during the operation of a given half-cell. (Which electrode is
dissolving, which electrode is gaining mass, which solution is getting more concentrated,
which solution is getting more dilute, which way and where are the electrons traveling, which
way and where are the positive ions traveling) Write a half-reaction for the process
occurring at each electrode.
Describe the relationship between voltage and the movement of electrons.
Calculate cell voltage/potentials from a table of standard electrode potentials.
Identify conditions that lead to corrosion and ways to prevent it.
Define the term electrolysis.
Know that in an electrolytic cell, electricity is used to force a nonspontaneous reaction to
occur. (electricity  nonspontaneous reaction). This is an endothermic process. What type
of energy is absorbed?
Identify the components of a fused salt cell and an electroplating cell and describe their
function. (anode, cathode, power supply, + and – electrodes – polarity is determined by
power supply) Write half-reactions for the process occurring at each electrode.
Describe the chemistry of a rechargeable cell.
Describe the process of electrolysis in the decomposition of water.
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Describe the electrolysis of a brine solution and predict possible products for a given cell.
Know these differences between voltaic and electrolytic cells:
o Voltaic cell: the redox reaction is spontaneous and exothermic
o Electrolytic cell: the redox reaction is nonspontaneous and endothermic.
o Voltaic cell: Anode is negative, cathode is positive.
o Electrolytic cell: Anode is positive, cathode is negative.
Know these similarities between voltaic and electrolytic cells:
o Both use redox reactions.
o The anode is the site of oxidation.
o The cathode is the site of reduction.
o The electrons flow through the wire from the anode to the cathode.