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18 Cards in this Set
- Front
- Back
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Give an example of an exothermic and an endothermic reaction. |
The best example of an exothermic reaction is burning fuels. An endothermic reaction is thermal decomposition. |
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What is an endothermic reaction ? |
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What is an exothermic reaction ? |
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How do you work out the atom economy ? |
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What is batch and continuous production? |
Batch production only operates at certain times. An example of this is pharmaceutical drugs because they are complicated to make and there is a fairly low demand for them. Continuous production runs all the time. An example of this is the Haber process for making ammonia. |
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How do you work out percentage yield ? |
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What happens in an exothermic reaction?
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The energy released in bond formation is greater than the energy use in breaking old bonds.
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What happens in an endothermic reaction?
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The energy required to break bonds is greater than the energy released when new bonds are formed.
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What is the rate of reaction ?
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It is how fast the reactants are changed into products.
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Name a very slow reaction
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1. rusting of iron 2. chemical weathering |
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Give an example of a moderate speed reaction
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metal (e.g. magnesium) reacting with dilute acid to produce a gentle steam of bubbles.
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Give an example of a fast reaction
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Burning
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The rate of a reaction that produces a gas can be observed by measuring how quickly the gas is produced. There are two ways of doing it, what are they?
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1. measuring the change in mass- the mass will fall as the gas is released. 2. measure the volume of gas given off- use a gas syringe to measure the volume of gas after regular intervals. |
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What does a rate of reaction depend on?
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1. the collision frequency of reacting particles 2. the energy transferred during a collision. |
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What are allotropes?
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Allotropes are different structural forms of the same element.
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Why are diamonds used for jewellery and cutting tools? |
Diamonds are sparkly and colourless which are ideal for jewellery. Each carbon atom has four covalent bonds in a very rigid giant covalent structure, which makes diamonds very hard and ideal for cutting tools.
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Why do diamonds not conduct electricity?
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It has no free ions/ electrons
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