What is activation energy ?

What is activation energy ?
by

1 Answer

Answer :

The amount of energy that a part of the reactant gains more than the average energy of the reactant due to mutual collision or any other means and acquires the ability to participate in the reaction is called activation energy.
by

Related questions

State the role of activated complex in a reaction and state the relation with energy of activation.

Description : State the role of activated complex in a reaction and state the relation with energy of activation.

Last Answer : Ans.: When the colliding reactant molecules possess the kinetic energy equal to energy of activation then the configuration of atoms of the species at this state is different from the reactants as well as ... barrier means the activated complex is difficult to form and it is a slow reaction.  

Define activation energy.

Description : Define activation energy.

Last Answer : Ans.: It is defined as extra energy to be supplied to the reactants so that they can change into products. 

The reaction step that has its transition state at the highest point on the reaction coordinate is the called the __________. (a) rate-determining step (b) activation energy (c) transition step (d) product favored step

Description : The reaction step that has its transition state at the highest point on the reaction coordinate is the called the __________. (a) rate-determining step (b) activation energy (c) transition step (d) product favored step

Last Answer : rate-determining step

An increase in which of the following results in a decrease in the rate of the chemical reaction? (a) temperature (b) concentration (c) collision frequency (d) energy of activation

Description : An increase in which of the following results in a decrease in the rate of the chemical reaction? (a) temperature (b) concentration (c) collision frequency (d) energy of activation

Last Answer : energy of activation

Which of the following is incorrect about heterogeneous catalysis? a. The most effective catalysts are those which have small surface area b. Seperation of catlyst is easy c. Increase in the rate of reaction is due to decrease in the activation energy d. It is based upon the phenomenon of adsorption

Description : Which of the following is incorrect about heterogeneous catalysis? a. The most effective catalysts are those which have small surface area b. Seperation of catlyst is easy c. Increase in the rate of reaction is due to decrease in the activation energy d. It is based upon the phenomenon of adsorption

Last Answer : a. The most effective catalysts are those which have small surface area

What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential energy of the reactants decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.

Description : What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential ... decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.

Last Answer : A The reaction follows an alternative pathway of lower activation energy.

Which one of the following statements regarding a catalyst is not correct? A An enzyme is a catalyst that only binds certain substrates. B An enzyme is a protein that is a highly efficient catalyst for one or more chemical reactions in a living system. C Catalysts increase the rate of a reaction by altering the mechanism, thereby increasing the activation energy. D Catalysts do not alter the equilibrium constant for a chemical reaction.

Description : Which one of the following statements regarding a catalyst is not correct? A An enzyme is a catalyst that only binds certain substrates. B An enzyme is a protein that is a highly ... increasing the activation energy. D Catalysts do not alter the equilibrium constant for a chemical reaction.

Last Answer : C Catalysts increase the rate of a reaction by altering the mechanism, thereby increasing the activation energy.

How does the metal activation series help build electromagnets ?

Description : How does the metal activation series help build electromagnets ?

Last Answer : Two electric gates are required for the construction of any type of cell. One causes oxidation and the other oxidation. That is, the tendency of one electron to leave electrons and become ionized ... cathode. Thus the basic idea of making anode and cathode is found through the activation series.

What is Activity Series ? What is the activation series ?

Description : What is Activity Series ? What is the activation series ?

Last Answer : The series that is obtained by sorting the metals according to their activity is called activation series.

What do you mean by activation of adsorbant? How is it achieved?

Description : What do you mean by activation of adsorbant? How is it achieved?

Last Answer : Ans.: Activation of adsorbent means increase the extent of adsorption. It is achieved by the increase of surface area. 

In the chlorination of alkanes, the first step in which chlorine free radicals are produced is called (a) initiation(b) activation(c) propagation(d) deactivation:

Description : In the chlorination of alkanes, the first step in which chlorine free radicals are produced is called : (a) initiation (b) activation (c) propagation (d) deactivation

Last Answer : initiation

Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): Because the bonds of adsorbed molecules are broke

Description : Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): Because the bonds of adsorbed molecules are broke

Last Answer : Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): ... D. If both Assertion & Reason are False.

Energy for activation of amino acids during proteins synthesis comes from

Description : Energy for activation of amino acids during proteins synthesis comes from

Last Answer : Energy for activation of amino acids during proteins synthesis comes from A. ATP B. GTP C. CTP D. UTP

Which group of periodic table have large negative energy of activation ?

Description : Which group of periodic table have large negative energy of activation ?

Last Answer : Which group of periodic table have large negative energy of activation ? A. Alkali metal B. Zero group C. Halogen family D. Alkaline earth metal

What lowers activation energy in enzymes?

Description : What lowers activation energy in enzymes?

Last Answer : This is the most important concern of Biochemistry, theenzyme-catalyzed reactions. The main factor that lowers theactivation energy, is the catalysis. Catalysts act by reducing theactivation barrier for ... fold rate acceleration occurs only with asmall fraction of the energy of most covalent bonds.

If the activation energy of a biochemical reaction is lowered then?

Description : If the activation energy of a biochemical reaction is lowered then?

Last Answer : What is the answer ?

How many high-energy phosphate bond equivalents are required for amino acid activation in protein synthesis? (A) One (B) Two (C) Three (D) Four

Description : How many high-energy phosphate bond equivalents are required for amino acid activation in protein synthesis? (A) One (B) Two (C) Three (D) Four

Last Answer : Answer : B

In the process of activation of amino acids for protein synthesis, the number of high energy phosphate bond equivalent utilised is (A) 0 (B) 1 (C) 2 (D) 4

Description : In the process of activation of amino acids for protein synthesis, the number of high energy phosphate bond equivalent utilised is (A) 0 (B) 1 (C) 2 (D) 4

Last Answer : Answer : C

The energy required to start an enzymatic reaction is called (A) Chemical energy (B) Metabolic energy (C) Activation energy (D) Potential energy

Description : The energy required to start an enzymatic reaction is called (A) Chemical energy (B) Metabolic energy (C) Activation energy (D) Potential energy

Last Answer : Answer : C

An enzyme brings about (A) Decrease in reaction time (B) Increase in reaction time (C) Increase in activation energy (D) Reduction in activation energy

Description : An enzyme brings about (A) Decrease in reaction time (B) Increase in reaction time (C) Increase in activation energy (D) Reduction in activation energy

Last Answer : Answer : D

Enzymes increases the rate of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Description : Enzymes increases the rate of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Last Answer : Answer : B

An enzyme promotes a chemical reaction by (A) Lowering the energy of activation (B) Causing the release of heat which acts as a primer (C) Increasing molecular motion (D) Changing the free energy difference between substrate and product

Description : An enzyme promotes a chemical reaction by (A) Lowering the energy of activation (B) Causing the release of heat which acts as a primer (C) Increasing molecular motion (D) Changing the free energy difference between substrate and product

Last Answer : Answer : A

Enzymes increase the rates of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Description : Enzymes increase the rates of reactions by (A) Increasing the free energy of activation (B) Decreasing the energy of activation (C) Changing the equilibrium constant of the reaction (D) Increasing the free energy change of the reaction

Last Answer : Answer : B

Enzymes accelerate the rate of reactions by (A) Increasing the equilibrium constant of reactions (B) Increasing the energy of activation (C) Decreasing the energy of activation (D) Decreasing the free energy change of the reaction

Description : Enzymes accelerate the rate of reactions by (A) Increasing the equilibrium constant of reactions (B) Increasing the energy of activation (C) Decreasing the energy of activation (D) Decreasing the free energy change of the reaction

Last Answer : Answer : C

The difference between Threshold energy and average energy of the molecules is called activation energy. Ina chemical reaction lowers the rate of reaction the greater will be. The activation energy

Description : The difference between Threshold energy and average energy of the molecules is called activation energy. Ina chemical reaction lowers the rate of reaction the greater will be. The activation energy

Last Answer : How do you define the molecularity of a reaction ?

The catalytic power of enzymes is due to (a) the presence of amino acids in their structures (b) their high molecular weight (c) their ability to lower the activation energy of the reaction (d) their limited solubility in water and other solvents

Description : The catalytic power of enzymes is due to (a) the presence of amino acids in their structures (b) their high molecular weight (c) their ability to lower the activation energy of the reaction (d) their limited solubility in water and other solvents

Last Answer : Ans:(c)

A catalyst is a substance which (a) Changes the equilibrium of a reaction so that the concentration of the product increases (b) Increases the rate of reaction and increases the equilibrium concentration of products (c) Hastens the attainment of equilibrium (d) Increases the activation energy

Description : A catalyst is a substance which (a) Changes the equilibrium of a reaction so that the concentration of the product increases (b) Increases the rate of reaction and increases the equilibrium concentration of products (c) Hastens the attainment of equilibrium (d) Increases the activation energy

Last Answer : Ans:(c)

Molecular diffusion is caused by the (A) Transfer of molecules from low concentration to high concentration region (B) Thermal energy of the molecules (C) Activation energy of the molecules (D) Potential energy of the molecules

Description : Molecular diffusion is caused by the (A) Transfer of molecules from low concentration to high concentration region (B) Thermal energy of the molecules (C) Activation energy of the molecules (D) Potential energy of the molecules

Last Answer : (B) Thermal energy of the molecules

Which of the following step of translation does not consume a high energy phosphate bond? (a) Peptidyl transferase reaction (b) Aminoacyl tRNA binding to A-site (c) Translocation (d) Amino acid activation

Description : Which of the following step of translation does not consume a high energy phosphate bond? (a) Peptidyl transferase reaction (b) Aminoacyl tRNA binding to A-site (c) Translocation (d) Amino acid activation

Last Answer : (b) Aminoacyl tRNA binding to A-site

Which of the following step of translation does not consume a high energy phosphate bond? (a) Peptidyl transferase reaction (b) Aminoacyl tRNA binding to A-site (c) Translocation (d) Amino acid activation

Description : Which of the following step of translation does not consume a high energy phosphate bond? (a) Peptidyl transferase reaction (b) Aminoacyl tRNA binding to A-site (c) Translocation (d) Amino acid activation

Last Answer : (a) Peptidyl transferase reaction

Role of an enzyme in reactions is to/as (a) decrease activation energy (b) increase activation energy (c) inorganic catalyst (d) none of the above.

Description : Role of an enzyme in reactions is to/as (a) decrease activation energy (b) increase activation energy (c) inorganic catalyst (d) none of the above.

Last Answer : (a) decrease activation energy

The catalytic activity of enzymes is due to their capacity to lower the __________ energy. (A) Activation (B) Potential (C) Kinetic (D) None of these

Description : The catalytic activity of enzymes is due to their capacity to lower the __________ energy. (A) Activation (B) Potential (C) Kinetic (D) None of these

Last Answer : (A) Activation

When the reaction occurs in the diffusion controlled region, the apparent activation energy as measured is only __________ the true value. (A) Twice (B) Half (C) Equal (D) None of these

Description : When the reaction occurs in the diffusion controlled region, the apparent activation energy as measured is only __________ the true value. (A) Twice (B) Half (C) Equal (D) None of these

Last Answer : (B) Half

At a given value of E/R (ratio of activation energy and gas constant), the ratio of the rate constants at 500°K and 400°K is 2, if Arrhenius law is used. What will be this ratio, if transition state theory is used with the same value of ‘E/R’? (A) 1.6 (B) 2 (C) 2.24 (D) 2.5

Description : At a given value of E/R (ratio of activation energy and gas constant), the ratio of the rate constants at 500°K and 400°K is 2, if Arrhenius law is used. What will be this ratio, if transition state theory is used with the same value of ‘E/R’? (A) 1.6 (B) 2 (C) 2.24 (D) 2.5

Last Answer : (D) 2.5

The reactions of high molecularity are rare, because (A) Of very large activation energy of many bodies (B) Of low probability of many body collisions (C) Many body collisions are not favoured energetically (D) Of requirement of very large concentration for such reactions

Description : The reactions of high molecularity are rare, because (A) Of very large activation energy of many bodies (B) Of low probability of many body collisions (C) Many body collisions are not favoured energetically (D) Of requirement of very large concentration for such reactions

Last Answer : (B) Of low probability of many body collisions

The role of a catalyst in a chemical reaction is to change the (A) Equilibrium constant (B) Activation energy (C) Final products (D) Heat of reaction

Description : The role of a catalyst in a chemical reaction is to change the (A) Equilibrium constant (B) Activation energy (C) Final products (D) Heat of reaction

Last Answer : (B) Activation energy

Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in a reaction involving many steps is the fastest step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Description : Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in ... step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Last Answer : (A) A lower temperature favours the reaction of lower activation energy

Enzymes (a protein) are catalysts found in organisms. Its efficiency of catalysing a reaction is due to its capacity to lower the activation energy of the reaction. The enzyme ptyalin used for food digestion is present in (A) Blood (B) Saliva (C) Intestine (D) Gland

Description : Enzymes (a protein) are catalysts found in organisms. Its efficiency of catalysing a reaction is due to its capacity to lower the activation energy of the reaction. The enzyme ptyalin used for food digestion is present in (A) Blood (B) Saliva (C) Intestine (D) Gland

Last Answer : (B) Saliva

Pick out the wrong statement. (A) In a multistep reaction, the slowest step is the rate determining step (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature (C) Slow chemical reactions have generally high values of activation energy (D) Molecularity of a reaction cannot be zero but the order of a reaction can be zero

Description : Pick out the wrong statement. (A) In a multistep reaction, the slowest step is the rate determining step (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature (C ... energy (D) Molecularity of a reaction cannot be zero but the order of a reaction can be zero

Last Answer : (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature

In a reaction, the threshold energy is equal to (where, A = activation energy N = normal energy of reactants) (A) A (B) N (C) A + N (D) A - N

Description : In a reaction, the threshold energy is equal to (where, A = activation energy N = normal energy of reactants) (A) A (B) N (C) A + N (D) A - N

Last Answer : (C) A + N

Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the reaction is practically irreversible in nature (C) The intercept of the Arrhenius plot is called the 'activation energy' (D) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions

Description : Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the ... ) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions

Last Answer : (C) The intercept of the Arrhenius plot is called the 'activation energy

The excess energy of the reactants required to dissociate into products is known as the __________ energy. (A) Thermal (B) Activation (C) Threshold (D) Binding

Description : The excess energy of the reactants required to dissociate into products is known as the __________ energy. (A) Thermal (B) Activation (C) Threshold (D) Binding

Last Answer : (B) Activation

Photochemical reaction rate does not depend significantly on temperature, because (A) It is a reversible reaction (B) It is an exothermic reaction (C) The energy of reacting molecules exceeds the activation energy by absorption of light (D) None of these

Description : Photochemical reaction rate does not depend significantly on temperature, because (A) It is a reversible reaction (B) It is an exothermic reaction (C) The energy of reacting molecules exceeds the activation energy by absorption of light (D) None of these

Last Answer : (C) The energy of reacting molecules exceeds the activation energy by absorption of light

Pick out the correct statement. (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state (C) A photochemical reaction is catalysed by light (D) A chemical reaction occurs when the energy of the reacting molecule is less than the activation energy of the reaction

Description : Pick out the correct statement. (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state (C) A photochemical reaction is catalysed by ... occurs when the energy of the reacting molecule is less than the activation energy of the reaction

Last Answer : (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state

For a heterogeneous catalytic reaction (A) Free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction (B) A relatively small amount of catalyst can cause the conversion of large amount of reactants which does not mean that catalyst concentration is important (C) The catalyst does not form an intermediate complex with the reactant (D) The surface of the catalyst does not play an important role during reaction

Description : For a heterogeneous catalytic reaction (A) Free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction (B) A relatively small amount of catalyst ... with the reactant (D) The surface of the catalyst does not play an important role during reaction

Last Answer : (A) Free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction

Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the (A) Activation energy (B) Equilibrium constant (C) Heat of reaction (D) None of these

Description : Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the (A) Activation energy (B) Equilibrium constant (C) Heat of reaction (D) None of these

Last Answer : (A) Activation energy

A catalyst (A) Initiates a reaction (B) Lowers the activation energy of reacting molecules (C) Is capable of reacting with any one of the reactants (D) Cannot be recovered chemically unchanged at the end of a chemical reaction

Description : A catalyst (A) Initiates a reaction (B) Lowers the activation energy of reacting molecules (C) Is capable of reacting with any one of the reactants (D) Cannot be recovered chemically unchanged at the end of a chemical reaction

Last Answer : (C) Is capable of reacting with any one of the reactants

The reason why a catalyst increases the rate of reaction is that, it (A) Decreases the energy barrier for reaction (B) Increases the activation energy (C) Decreases the molecular collision diameter (D) None of these

Description : The reason why a catalyst increases the rate of reaction is that, it (A) Decreases the energy barrier for reaction (B) Increases the activation energy (C) Decreases the molecular collision diameter (D) None of these

Last Answer : (A) Decreases the energy barrier for reaction

If the pore diffusion controls in a catalytic reaction, the apparent activation energy Ea is equal to (A) The intrinsic activation energy E (B) (E + ED) where ED is activation due to diffusion (C) (E + ED)/2 (D) ED/2

Description : If the pore diffusion controls in a catalytic reaction, the apparent activation energy Ea is equal to (A) The intrinsic activation energy E (B) (E + ED) where ED is activation due to diffusion (C) (E + ED)/2 (D) ED/2

Last Answer : (D) ED/2