Q. 74.1( 30 Votes )
What is the effect of temperature on the rate constant of a reaction? How can this effect of temperature on rate constant be represented quantitatively?
Increase in temperature increases the rate constant of a reaction. as we know increase in temperature increases the rate of reaction to satisfy the equation Rate = k [concentration]n where n can be any real number. k have to increase as concentration is almost not changing over small temperature change. Increasing temperature by 100C almost double the rate constant.
This can be represented quantitively by the help of arrehinus equation-
K = Ae-Ea/RT, where k is rate constant, Ea is activation energy, R is universal gas constant, T is absolute temperature.
Rate this question :
Describe how does the enthalpy of reaction remain unchanged when a catalyst is used in the reaction.Chemistry - Exemplar
Explain the difference between instantaneous rate of a reaction and average rate of a reaction.Chemistry - Exemplar
Note: In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion : The enthalpy of reaction remains constant in the presence of a catalyst.
Reason : A catalyst participating in the reaction, forms different activated complex and lowers down the activation energy but the difference in energy of reactant and product remains the same.
Chemistry - Exemplar
Match the statements given in Column I and Column II
Column I Column II
(i) Catalyst alters the rate of reaction (a) cannot be fraction or zero
(ii) Molecularity (b) proper orientation is not there
(iii) Second half life of first order reaction (c) by lowering the activation
(iv) e–Ea/R T (d) is same as the first
(v) Energetically favourable reactions are sometimes slow (e) total probability is one
(vi) Area under the Maxwell Boltzman curve is constant (f) refers to the fraction of molecules with energy equal
to or greater than activation
Chemistry - Exemplar
Thermodynamic feasibility of the reaction alone cannot decide the rate of the reaction. Explain with the help of one example.Chemistry - Exemplar
Why does the rate of any reaction generally decreases during the course of the reaction?Chemistry - Exemplar
Which of the following statement is not correct for the catalyst?Chemistry - Exemplar
Which of the following statements are in accordance with the Arrhenius equation?Chemistry - Exemplar
Mark the incorrect statements.Chemistry - Exemplar