# Rate of Reactions

A small amount of flashcards to help people with the rate of reactions section in Thread of Life in OCR Salters Chemistry. Know I've been having trouble so hopefully it'll help others too

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What is the unit of rate?
moldm-3s-1
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What are the units of k, the rate constant?
Variable
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General rate equation is....
Rate = k [A]m [B]n
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Define 'Overall Order' of a reaction
All the orders in a reaction added together
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If a reactant has zero order, its concentration...
has no effect on the rate of reaction
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When studing rates of equations, what must be kept constant?
Temperature
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When one reactant double and the product produced doubles...
The order with respect to this reactant is 1
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When every half-life of [reactant] is the same, it is to Which order?
First
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In a two-step mechanism, which step is the RDS?
The one which requires the highest Activation Enthalpy
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On a [rate] vs Time graph, a straight line means:
Zero order
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Why does rate usually increase when [reactant] increases?
Greater frequency of collisions which increases the probability of collisions with higher than Ea THEREFORE faster rate
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How does rate change in an enzyme-catalysed reaction, depending on [substrate]?
Rises at first order then levels off to zero order.
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Why, at high [substrate], is the order w/ respect to [substrate] beocme zero?
Because the enzyme active sites are saturated and cannot work any faster.
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Why does doubling enzyme concentration double the rate?
Doubles number of active sites.
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## Other cards in this set

### Card 2

Variable

#### Back

What are the units of k, the rate constant?

### Card 3

#### Front

Rate = k [A]m [B]n

### Card 4

#### Front

All the orders in a reaction added together

### Card 5

#### Front

has no effect on the rate of reaction