Enzymes are destroyed, when the
(A) Temperature is very high
(B) Reactant's concentration is very high
(C) Reactant's concentration is very low
(D) Reaction rate is independent of the reactant's concentration

1 Answer

Answer :

(A) Temperature is very high

Related questions

Description : At very high concentration of enzymes, the rate of fermentation chemical reaction is __________ the concentration of reactants. (A) Independent of (B) Directly proportional to (C) Inversely proportional to (D) Proportional to the square of

Last Answer : (A) Independent of

Description : Pick out the wrong statement. (A) Wine, rum & Vodka are prepared by the formulation of fruit juice, sugar beet & rye respectively (B) Protein catalysts are called enzymes (C) The rate ... concentration of reactants at high concentration of enzymes (D) Total sugar content in molasses is about 10%

Last Answer : (D) Total sugar content in molasses is about 10%

Description : Rate of a chemical reaction is independent of the concentration of the reactants for a __________ reaction. (A) Zero order (B) Third order (C) Consecutive (D) None of these

Last Answer : (A) Zero order

Description : . In a zero order reaction, reactants concentration does not change with time and the (A) Time for half change is half the time taken for completion of the reaction (B) Time for ... is independent of the initial concentration (D) Reaction rate is trebled when the initial concentration is trebled

Last Answer : (A) Time for half change is half the time taken for completion of the reaction

Description : Specific rate constant for a second order reaction (A) Is independent of temperature (B) Varies with temperature (C) Depends on the nature of the reactants (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Description : Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants; but it is afunction of reaction temperature. In a chemical reaction, the time required to ... Then the order of this reaction is: (A) 0 (B) 1 (C) 2 (D) 3

Last Answer : (B) 1

Description : The rate constant of a chemical reaction decreases by decreasing the (A) Pressure (B) Concentration of reactants (C) Temperature (D) Duration of reaction

Last Answer : (C) Temperature

Description : Rate of a chemical reaction is not influenced by the (A) Catalyst (B) Temperature (C) Reactants concentration (D) Number of molecules of reactants taking part in a reaction

Last Answer : (D) Number of molecules of reactants taking part in a reaction

Description : 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

Last Answer : (D) Free energy of activation is higher

Description : The rate constant of a reaction is a function of the (A) Time of reaction (B) Temperature of the system (C) Extent of reaction (D) Initial concentration of the reactants

Last Answer : (B) Temperature of the system

Description : The rate constant of a reaction depends on the (A) Initial concentration of reactants (B) Time of reaction (C) Temperature of the system (D) Extent of reaction

Last Answer : All of the carbon atoms are sp hybridized

Description : The rate constant of a reaction depends on the (A) Initial concentration of reactants (B) Time of reaction (C) Temperature of the system (D) Extent of reaction

Last Answer : (C) Temperature of the system

Description : The rate constant of a chemical reaction increases by increasing the (A) Temperature (B) Pressure (C) Reactant's concentration (D) None of these

Last Answer : (A) Temperature

Description : Rate of a chemical reaction is not affected by the (A) Catalyst (B) Temperature (C) Reactant’s concentration (D) Number of molecules of reactants taking part in the reaction

Last Answer : (D) Number of molecules of reactants taking part in the reaction

Description : The order of reaction is the number of moles whose concentrations determine the rate of a reaction at a given temperature Give the integrated equation for first order reaction. K = (2.303 / t) * log (a ... a' is the initial concentration of reactants x' is the amount reacted in time t seconds

Last Answer : What is Threshold energy ?

Description : The rate of a chemical reaction can be affected by: w) temperature x) concentration of products y) concentration of reactants z) all of the above

Last Answer : ANSWER: Z -- ALL OF THE ABOVE

Description : Which of the following set of conditions is favourable for the maximum yield of ammonia by Haber's process? (A) High pressure, low reactants concentration, high temperature (B) High ... , high reactants concentration, low temperature (D) Low pressure, high reactants concentration, low temperature

Last Answer : (C) High pressure, high reactants concentration, low temperature

Description : According to the 'law of mass action', the rate of reaction is directlyproportional to the (A) Equilibrium constant (B) Volume of the reaction vessel (C) Nature of the reactants (D) Molar concentration of the reactants

Last Answer : (D) Molar concentration of the reactants

Description : Velocity of a reaction depends upon the (A) Nature of the reactants (B) Concentration of the reactants (C) Temperature at which the reaction is carried (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Velocity of a chemical reaction (A) Decreases with increase in temperature (B) Increases with increase of pressure of reactants for all reactions (C) Decreases with increase of reactant concentration (D) None of these

Last Answer : (D) None of these

Description : Which of the following is not true regarding enzymes? (A) They catalyze only a particular type of reaction (B) They remain active even after separation from the source (C) They are destroyed ... They are irreversibly destroyed at high temperature (E) Their activity depends on the pH of the solution

Last Answer : Answer : C

Description : It is important to balance the chemical equations to satisfy the law of conservation of mass. Which of the following statements of the law is incorrect? (a) The total mass of the elements present in ... the reaction (d) Mass can neither be created nor can it be destroyed in a chemical Reaction.

Last Answer : Answer : (c) The chemical composition of the reactants is the same before and after the reaction

Description : What affect does the concentration of reactants have on the rate of a reaction?

Last Answer : Need answer

Description : 25. In a reaction, A + B  Product, rate is doubled when the concentration of B is doubled, and rate increases by a factor of 8 when the concentrations of both the reactants (A and B) are doubled, rate law for the reaction can be ... Rate = k[A] [B]2 (3) Rate = k[A]2 [B]2 (4) Rate = k[A] [B]

Last Answer : Rate = k[A]2 [B] (

Description : Semibatch reactor is preferred, when a/an (A) A highly exothermic reaction is to be controlled (B) Undesirable side reaction (at high concentration of one of the reactants) is to be avoided (C) A gas is to be reacted with liquid (e.g. hydrogenation of fat) (D) All (A), (B), and (C

Last Answer : (D) All (A), (B), and (C

Description : The reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m3 is fed to the reactor at the rate of 0.01 m3 /s and at a temperature of 500 K. If the exit ... /kmole. K (may be assumed to be independent of temperature)) (A) 400 (B) 500 (C) 600 (D) 1000

Last Answer : (C) 600

Description : Reverse reaction in a chemical equilibrium is favoured by the (A) Removal of one of the products regularly (B) Increase in the concentration of one of the products (C) Increase in the concentration of one of the reactants (D) None of these

Last Answer : (B) Increase in the concentration of one of the products

Description : In a reversible chemical reaction having two reactants in equilibrium, if the concentration of the reactants are doubled, then the equilibrium constant will (A) Remain the same (B) Be halved (C) Also be doubled (D) Become one fourth

Last Answer : (A) Remain the same

Description : Which of the following will favour the reverse reaction in a chemical equilibrium reaction? (A) Increasing the concentration of one of the reactants (B) Increasing the concentration of one or more of the products (C) Removal of at least one of the products at regular interval (D) None of these

Last Answer : (B) Increasing the concentration of one or more of the products

Description : For a zero order chemical reaction, the (A) Half life period is directly proportion to the initial concentration of the reactants (B) Plot of products concentration with time is a straight line through the origin (C) Products concentration increases linearly with time (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

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

Description : If the time required to complete a definite fraction of reaction varies inversely as the concentration of the reactants, then the order of reaction is (A) 1 (B) 2 (C) 3 (D) 4

Last Answer : (B) 2

Description : What is the order of a chemical reaction in which doubling the initial concentration of the reactants doubles the half life time of the reaction? (A) 0 (B) 1 (C) 2 (D) 3

Last Answer : (A) 0

Description : Organic molecules that increase the rate of metabolic reactions with themselveschangingareknown as A- coenzymes B- enzymes C- substrates D- .reactants

Last Answer : enzymes

Description : Pick out the wrong statement. (A) In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time (B) In a semi-batch reactor, ... system (D) In a continuous flow reactor, both the reactants and the products flow out continuously

Last Answer : (C) In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system

Description : Enzymes are a. Inorganic compounds. b. Destroyed in a reaction. b. Proteins. a. Vitamins.

Last Answer : c

Description : Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of ... to (B) Independent of (C) Inversely proportional to (D) Proportional to the square o

Last Answer : (A) Proportional to

Description : Arrhenius equation K = Ae-E a / R T In some reactions, Rate of reaction is directly proportional to. Concentration of catalyst Catalyst used in Bio-Chemical reactions is called. Enzymes Reactions catalyzed by light are called as. Photo catalyzed or Photosensitised reactions

Last Answer : Define order of reaction

Description : The rate of an enzyme catalyzed reaction was measured using several substrate concentrations that were much lower than Km, the dependence of reaction velocity on substrate concentration can best be ... constant fraction of Vmax (C) Equal to Km (D) Proportional to the substrate concentration

Last Answer : Answer : C

Description : The Michaehis-Menten hypothesis: (A) Postulates the formation of an enzyme substrate complex (B) Enables us to calculate the isoelectric point of an enzyme (C) States that the ... independent of substrate concentration (D) States that the reaction rate is proportional to substrate concentration

Last Answer : Answer : A

Description : Though kinetics of ammonia synthesis dictates the use of low temperature for high equilibrium conversion, yet it is kept moderately high (550°C), because at low temperature (A) Rate of reaction is very low ... (C) Space velocity of gas is very low resulting in decreased conversion (D) None of these

Last Answer : (A) Rate of reaction is very low

Description : In an exothermic chemical reaction, the reactants compared to the products have (A) Higher temperature (B) More energy (C) Less energy (D) Same energy

Last Answer : (B) More energy

Description : Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the ... energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Last Answer : (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products

Description : The equilibrium constant ‘K’ of a chemical reaction depends on (A) Temperature only (B) Pressure only (C) Temperature and pressure (D) Ratio of reactants

Last Answer : (A) Temperature only

Description : If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will (A) Increase (B) Decrease (C) Remain unaltered (D) Increase or decrease; depends on the particular reaction

Last Answer : (C) Remain unaltered

Description : 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 ... compound is defined as the heat of reaction leading to the formation of the compound from its reactants

Last Answer : (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

Description : Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence ... D) Half life of a reaction increases with increased initial concentration for reaction orders more than one

Last Answer : (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same

Description : In autocatalytic reactions, (A) One of the reactants acts as a catalyst (B) One of the products acts as a catalyst (C) Catalysts have very high selectivity (D) No catalyst is used

Last Answer : (B) One of the products acts as a catalyst

Description : Enzymes are different from catalysts in (A) Being proteinaceous (B) Not used up in reaction (C) Functional at high temperature (D) Having high rate of diffusion

Last Answer : Answer : A

Description : What causes pressure changes of reactants to affect reaction rate?

Last Answer : The frequency of collisions is changed.