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9 Cards in this Set
- Front
- Back
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A chemical reaction can be accompanied by an enthalpy change. What are the names?
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Exothermic and endothermic
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What is the importance of oxidation?
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It is important as an exothermic process in the combustion of fuels and the oxidation of carbohydrates such as glucose in respiration
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What do endothermic processes require?
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An input of heat energy, e.g. the thermal decomposition of calcium carbonate
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What is 'activation energy'?
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The minimum energy required to start a reaction by the breaking of bonds
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What are the 'standard conditions'?
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A pressure of 100 kPa (1 atmosphere) a stated temperature, usually 298k (25*c), and a concentration of 1 mol dm^-3 (for reactions with aqueous solutions)
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Define 'enthalpy change of reaction'
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The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states
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Define 'enthalpy change of formation'
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The enthalpy change that takes place when one mole of a compound in its standard state is formed form its constituent elements in their standard states under standard conditions
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Define 'enthalpy change of combustion'
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The enthalpy change that takes place when one mole of a substance reactions completely with oxygen under standard conditions, all reactants and products being in their standard states
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Define 'average bond enthalpy'
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The average enthalpy change that takes place when breaking by homolytic fission 1 mol of a given type of bond in the molecules of a gaseous species
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