Chemical Kinetics
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Which one of the given statement for order of reaction is not correct?
Which one of the given statement for order of reaction is not correct?
What is the difference between reaction rate and rate constant?
What is the difference between reaction rate and rate constant?
Reaction rate is used to measure how fast or slow reactions occur per unit time. The rate constant is a proportionality factor that remains constant for every reaction.
Upvote 
Can the order and molecularity of a reaction be the same?
Can the order and molecularity of a reaction be the same?
Yes, in elementary reactions, order and molecularity can be the same, but this is not always the case because order is an experimental quantity, and molecularity is a theoretical concept.
Upvote Reaction Kinetics, also known as chemical kinetics, is the study of the rate of chemical reaction and the factors affecting the reaction rate, such as temperature, concentration, and catalyst.
Upvote For the first order reaction A → 2B, 1 mole of reactant A gives 0.2 moles of B after 100 minutes. The half life of the reaction is _____ min. (Round off to the Nearest Integer).
[Use : ln2 = 0.69, ln 10 = 2.3 Properties of logarithms : ln x? = y ln x; ln(x/y) = lnx – lny ]
For the first order reaction A → 2B, 1 mole of reactant A gives 0.2 moles of B after 100 minutes. The half life of the reaction is _____ min. (Round off to the Nearest Integer).
[Use : ln2 = 0.69, ln 10 = 2.3 Properties of logarithms : ln x? = y ln x; ln(x/y) = lnx – lny ]
A → 2B
t = 0: 1 mole 0
after 100 min: (1 - 0.1) mol 0.2 mol
K = (1/t)ln [a/ (a-n)]
K = (2.303/100)log (1/0.9) min? ¹
0.693/t? /? = (2.303/100) [log10 - log9] = (2.303/100) x 0.046
t? /? = 69.3 / (2.303 x 0.046) = 654.15 min
Ans. = 654 (the nearest integer)
Upvote Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: A reaction can have zero activation energy.
Reason R: The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy.
In the light of the above statements, choose the correct answer from the options given below:
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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: A reaction can have zero activation energy.
Reason R: The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy.
In the light of the above statements, choose the correct answer from the options given below:
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A reaction can have zero activation energy, for example, •CH? + •CH? → CH? − CH? has zero activation energy.
Upvote For a certain reaction, the rate = k[A]2[B]. When the initial concentration of A is tripled keeping concentration of B constant, the initial rate would
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For a certain reaction, the rate = k[A]2[B]. When the initial concentration of A is tripled keeping concentration of B constant, the initial rate would
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Let the new rate be, R'.
A' = [3 A], B' = [B]
R' = K [A']² [ B']
= K [3 A]² [ B]
= 9 K [ A]² [ B]
= 9 * R
Hence, rate would become nine times.
Upvote The number of molecules with energy greater than the threshold energy for a reaction increases five fold by a rise of temperature from 27°C to 42°C. Its energy of activation in J/mol is (Take in 5 = 1.6094; R = 8.314 J mol⁻¹ K⁻¹)
The number of molecules with energy greater than the threshold energy for a reaction increases five fold by a rise of temperature from 27°C to 42°C. Its energy of activation in J/mol is (Take in 5 = 1.6094; R = 8.314 J mol⁻¹ K⁻¹)
k = Ae? Ea/RT
ln (K? /K? ) = (Ea/R) [1/T? - 1/T? ]
ln (5) = (Ea/8.314) [1/300 - 1/315]
1.6094 = (Ea/8.314) [15 / (300 × 315)]
Ea = 84297 J
Upvote For a reaction of order n, the unit of the rate constant is:
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For a reaction of order n, the unit of the rate constant is:
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Rate = K [A]?
K = Rate / [A]?
= (mole L? ¹s? ¹) / (mole L? ¹)?
= mole¹? L? ¹ s? ¹
Unit of K: mole¹? L? ¹ s? ¹
Upvote