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24 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Define a redox reaction. |
A réaction in which both oxidation and reduction occur. |
c'mon man it's in the name. |
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Define Oxidation in all ways possible |
-Addition of Oxygen -Removal of Hydrogen -Loss of electrons -Increase in oxidation number/state |
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Define Reduction |
-Removal of Oxygen -Addition of Hydrogen -Gain of electrons -Decrease in oxidation state |
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Give one common example of oxidation. |
Rusting or combustion |
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What is the oxidation number of Oxygen in O2? |
0, all few elements have an oxidation number of 0. |
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What is the oxidation number of Na in NaOH? |
+1, all Group I and Group II elements have oxidation numbers equal to their group number. |
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What's the oxidation state of H in NaH? |
-1, Hydrogen always has an oxidation number of +1 except in metal hydrides like NaH |
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What is the oxidation number of O in H²O²? |
-1, Oxygen also has an oxidation number of -2 except in peroxide compounds |
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What is the oxidation number rule for Group VII elements? |
Always -1, except in compounds with more electronegative elements |
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What is the oxidation number of NaOH? |
0, the oxidation number of a molecule is equal to the overall charge on the molecule |
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What's a reducing agent? (Give examples) |
A species that reduces another species in a reaction and is therefore oxidised. Ex, NaBH⁴, LiAlH⁴ |
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What's a oxidising agent? (Give examples) |
A species that oxidises another species in a reaction and is therefore reduced. Ex, K²Cr²O⁴ |
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List the steps to balancing a redox reaction. |
-Split into reduction and Oxidation halves. -Balance the oxidised and reduced species. -Balance oxygen by adding H²O to the appropriate side. -Balance hydrogen by adding H+ to the appropriate side. . -Balance charge by adding electrons. -Manipulate coefficients to make electrons cancel out. -Add the two halves together. |
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What is disproportionation? |
A reaction in which one compound is both reduced and oxidised into two products. |
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What is the activity series? |
A ranking of elements based on the ease of oxidation. |
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Give two types of electrochemical cross and what they do. |
Voltaic cell: converts spontaneous chemical energy into electrical energy. Electrolytic cell: uses electrical energy to start non-spontaneous chemical reactions. |
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What is an electrode? |
A conducting material used to make contact with the non-metallic parts of the cell. |
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What are the two types of electrode (and what do they do)? |
Anode: Oxidation Cathode: Reduction |
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What is a metal/metal ion electrode? |
A bar of metal dipped in a solution of its ions. |
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Describe a voltaic cell. |
-Two half cells where oxidation and reduction occur separately. -An external circuit/wire for the exchange of electrons. -A salt bridge (usually made of agar) to prevent charge build-up |
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Give examples of salt bridges. |
KCl and KNO³ |
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Describe an electrolytic cell. |
-An electrolyte to be electrolysed. -A battery. -Two (inert) electrodes connected to a battery and dipped in the electrolyte. -A porous membrane. |
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Give two examples of electrode materials. |
Graphite and platinum |
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What is electrolysis? |
The decomposition of a compound by passing electric current through is molten or aqueous form. |
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