Catalytic converters made of palladium (Pd) reduce automobile pollution by catalyzing the reaction between unburned hydrocarbons
and oxygen. How does Pd increase the rate of this reaction?
A: By cooling the reactants
B: By splitting the oxygen atoms
C: By giving the hydrocarbons a negative charge
D: By decreasing the activation energy
A: By cooling the reactants
B: By splitting the oxygen atoms
C: By giving the hydrocarbons a negative charge
D: By decreasing the activation energy
2 answers:
Answer: D: By decreasing the activation energy
Explanation: A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and convert to products.
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.
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Explanation:
According to the given data, we will calculate the following.
Half life of lipase = 8 min x 60 s/min
= 480 s
Rate constant for first order reaction is as follows.
=
Initial fat concentration = 45
= 45 mmol/L
Rate of hydrolysis = 0.07 mmol/L/s
Conversion X = 0.80
Final concentration (S) =
= 45 (1 - 0.80)
= 9
or, = 9 mmol/L
It is given that = 5mmol/L
Therefore, time taken will be calculated as follows.
t =
Now, putting the given values into the above formula as follows.
t =
=
=
= 27.38 min
Therefore, we can conclude that time taken by the enzyme to hydrolyse 80% of the fat present is 27.38 min.