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Flashcards in Mrs Sedgley F334 Deck (10)
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1

Explain what is meant by a chemical being first order

As the concentration of the chemical doubles, the rate of reation also doubles, as long as all other chemicals have constant concentrations

2

Explain what is meant by a chemcial being second order

As the concentration of the chemical doubles, the rate of reaction quadrouples, as long as all other chemicals have constant concentrations

3

If the rate of a reaction is not affected by the use of a chemical what order is that chemical? And is it shown in the rate equation?

Zero order
Not included in the rate equation

4

How is the order of each chemical in a reaction caluclated?

Change the concentration of one reactant, and keep the others in excess / constant concentrations (so they have no affect)
Plot a graph of the initial rates (conc / time)
Calculate the half life
If the half life is equal = First order
If the half life doubles = Second order
If there is no half life = Zero order

5

What is the rate determining step (RDS) of a reaction?

The slowest step in the reaction, and so limits the rate

6

What does the order of each chemical tell us about the RDS?

The number of molecules of reactant that are used
Eg, [O2]2 = 2O2

7

True or false? If a chemical is in the rate equation, it is also in the RDS?

True

8

What is Competitive inhibition in terms of enzymes?

When a molecule has a similar shape to the real substrate , and can bind to the active site, and so blocks the real subtrate from binding (so reduces the rate of reaction)

9

If in a reaction, involving an enzyme, has a low substrate concentration, what is the Rate equation / RDS?

Rate = k[E] [S]
RDS = E + S >>> ESC

10

If in a reaction, involving an enzyme, has a high substrate concentration, what is the rate equation / RDS?

Rate = k[E]
RDS = ESC >>> EPC