Term
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Definition
| The energy required to start a reaction For example, you must heat paper before burning occurs. (Burning is a chemical reaction between the paper and oxygen.) |
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Term
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Definition
| The state of disorder or randomness of particles. A major driving force in reactions is to increase entropy. |
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Term
List in order of increasing entropy:
gas
liquid
solid |
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Definition
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Term
| List five factors that control reaction rate |
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Definition
nature of reactants
surface area exposed
concentrations
temperature
presence of catalyst |
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Term
| State the collision theory of reaction rates. |
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Definition
There must be collisions between reactants.
Reaction rate depends on number of collisions per unit time and the percent which are successful (have sufficient energy). |
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Term
| How is the reaction rate related to concentration? |
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Definition
| Reaction rate is directly proportional to the concentrations of reactants. |
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Term
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Definition
| A catalyst is introduced into a reaction to speed it up or slow it down. It is not consumed. An increase or decrease of activation energy results from an alternate reaction path. |
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Term
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Definition
| The rate of a chemical reaction is proportional to the product of the concentrations of the reactants, each raised to the appropriate power. |
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Term
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Definition
| Symbol is "k" in a rate equation. A constant specific to temperature and reaction which is part of every rate equation. |
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Term
| How is the order of a reaction calculated? |
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Definition
| By adding the exponents in the reaction rate equation. Rate = k[H2][I2] |
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Term
| What is the order of H2 + I2 ↔ 2HI |
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Definition
1 + 1 = 2
Reaction is second order.
(note: the exponents of the concentrations of H2 and I2, are obtained experimentally, not from their coefficients in a balanced chemical reaction.) |
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