The minimum energy required to allow a chemical reaction to proceed is termed as the 'threshold energy '. Chemical reactions with low activation energy are: (A) Always irreversible (B) Insensitive to temperature changes (C) Mostly irreversible (D) Highly temperature sensitive

The minimum energy required to allow a chemical reaction to proceed
is termed as the 'threshold energy '. Chemical reactions with low activation
energy are:
(A) Always irreversible
(B) Insensitive to temperature changes
(C) Mostly irreversible
(D) Highly temperature sensitive
by

1 Answer

Answer :

(B) Insensitive to temperature changes
by

Related questions

Reactions with high activation energy are (A) Very temperature sensitive (B) Temperature insensitive (C) Always irreversible (D) Always reversible

Description : Reactions with high activation energy are (A) Very temperature sensitive (B) Temperature insensitive (C) Always irreversible (D) Always reversible

Last Answer : (A) Very temperature sensitive

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

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

The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the __________ energy. (A) Activation (B) Potential (C) Binding (D) Threshold

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Last Answer : (A) Activation

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

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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.

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

Proteins that cause reactions to proceed more rapidly and lower the energy of activation are called.

Description : Proteins that cause reactions to proceed more rapidly and lower the energy of activation are called.

Last Answer : ANSWER: ENZYMES

The reaction rate almost gets doubled for 10°C rise in temperature. This is due to the fact that the (A) Increased temperature reduces the activation energy (B) Fraction of molecules having threshold energy increases (C) Collision frequency increases (D) Value of threshold energy decreases

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Last Answer : (B) Fraction of molecules having threshold energy increases

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

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If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower(C) Entropy changes(D) Free energy of activation is higher

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

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Last Answer : (B) Activation

The energy of activation of a chemical reaction: (A) Is same as heat of reaction at constant pressure (B) Is the minimum energy which the molecules must have before the reaction can take place (C) Varies as fifth power of the temperature (D) Both (B) and (C)

Description : The energy of activation of a chemical reaction: (A) Is same as heat of reaction at constant pressure (B) Is the minimum energy which the molecules must have before the reaction can take place (C) Varies as fifth power of the temperature (D) Both (B) and (C)

Last Answer : (B) Is the minimum energy which the molecules must have before the reaction can take place

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

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Threshold energy in a reaction is equal to the (A) Activation energy (B) Normal energy of reactants (C) Sum of (A) & (B) (D) Neither (A) nor (B)

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The minimum amount of energy required for the reaction to takes place is called threshold energy.

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

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Why is being insensitive a basis for criticism, and being overly sensitive also a basis for criticism?

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If a tree flowers thrice in a year (Oct, Jan and July) in Northern India, it is said to be (a) photo and thermo-insensitive (b) photo and thermo-sensitive (c) photosensitive but thermo-insensitive (d) thermosensitive but photo-insensitive

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If the price elasticity of a product is greater than 1, we can say that (a) The products demand is sensitive to price variation; (b) Product demand is insensitive to price variation; (c) Demand and price move in same directions ; (d) None of this

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What can you say about the following statements? I. XML tags are case-insensitive. II. In JavaScript, identifier names are case-sensitive. III. Cascading Style Sheets (CSS) cannot be used with XML. IV. All well-formed XML documents must contain a document type definition. (1) only I and II are false. (2) only III and IV are false. (3) only I and III are false. (4) only II and IV are false.

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Last Answer : Answer: Marks to all

Pick out the correct statement. (A) If an insoluble gas is passed through a volatile liquid placed in a perfectly insulated container, the temperature of the liquid will increase (B) A process is irreversible as long as Δ S for the system is greater than zero (C) The mechanical work done by a system is always equal to∫P.dV (D) The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants

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Pick out the correct statement. (A) A catalyst does not change AH of the reaction (B) A catalyst changes the equilibrium point (C) Law of mass action was suggested by Le-Chatelier (D) The difference between the energy of reactants and that of the products is the activation energy

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Last Answer : (A) A catalyst does not change AH of the reaction

In case of a/an __________ chemical reaction, conversion increases with the rise in temperature. (A) Reversible exothermic (B) Irreversible exothermic (C) Irreversible endothermic (D) Reversible endothermic

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Last Answer : Answer : B

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

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A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively) (A) Δ S1is always < Δ SR (B) Δ S1is sometimes > Δ SR (C) Δ S1is always > Δ SR (D) Δ S1is always = Δ SR

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Last Answer : (C) Δ S1is always > Δ SR

The minimum energy required to eject an electron from a metal surface is called a) Intensity b) Threshold frequency c) Work function d) Photo energy

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Last Answer : c) Work function

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

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

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Last Answer : Ans:(c)

An endothermic aqueous phase first order irreversible reaction is carried out in an adiabatic plug flow reactor. The rate of reaction: (A) Is maximum at the inlet of the reactor (B) Goes through a maximum along the length of the reactor (C) Goes through a minimum along the length of the reactor (D) Is maximum at the exit of the reactor

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Last Answer : (A) Is maximum at the inlet of the reactor

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

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Last Answer : (B) Activation energy

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

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Last Answer : (A) Activation energy

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

Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to iron catalyst in ammonia synthesis reaction (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction

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A catalyst in a chemical reaction (A) Decreases the activation energy (B) Alters the reaction mechanism (C) Increases the frequency of collisions of reacting species (D) All (A), (B) and (C)

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Last Answer : (D) Equal to or more than

A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction. (A) Less than (B) Equal to (C) More than(D) Equal to or more than

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Last Answer : (D) Equal to or more than