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13 Cards in this Set
- Front
- Back
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What is a redox reaction? |
When reduction and oxidation happen at the same time. Oxidising agent gains electrons, donated by the reducing agent. |
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How can we define the reactivity gap of the displacing substance and the substance being displaced? |
The bigger the gap the higher reactivity gap. |
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Equation of rusting? |
Iron + Oxygen + Water - - > Hydrated Iron (III) Oxide. |
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How does the redox reaction in rusting work? |
Iron loses electrons when it reacts with oxygen. |
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How does the sacrificial method work? |
A more reactive metal is used to coat the iron so it reacts with them rather than the iron. |
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How does a Hydrogen-Oxygen fuel cell work? |
At negative cathode the oxygen coming in gains electrons and reacts with the water in the Potassium Hydroxide electrolyte to form OH- ions. The Oxygen gas gains electrons. At the positive anode the hydrogen reacts with the Hydroxide ions to form water. The Hydrogen gas loses electrons. |
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What are the equations for a Hydrogen-Oxygen fuel cell |
At the cathode: O2 + 4e- + 2H20 - - > 4OH- At the anode: 2H2 + 4OH- - - > 4H2O + 4e- Overall: 2H2 + O2 - - > 2H20 |
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Advantages of Hydrogen-Oxygen fuel cells? (4) |
Efficient. Energy out is electrical so no turbines need to be moved which decrease efficiency as it loses energy from friction. No pollution. Very few stages so very few places to lose heat. |
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Why are the Hydrogen-Oxygen fuel cells used in spacecraft? |
Can create drinking water. |
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What are the first few alcohols? |
Methanol. Ethanol. Propanol. Butanol. Pentanol. |
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What is the structure of an alcohol? |
An alkane with an oxygen between one of the carbons and one of the hydrogens. |
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How can ethanol be made by hydrating ethane? |
Ethane and steam is reacted at high temperature and high pressure using phosphoric acid as the catalyst. |
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How can ethanol be converted back into ethane? |
Ethanol vapour is passed over a hot aluminium oxide catalyst. |
