A catalyst increases rate of reaction by

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A catalyst increases rate of reaction by A. Decreasing enthalpy B. Decreasing internal ... activation energy D. Increasing activation energy

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Description : When a catalyst increases the rate of chemical reaction the rate constant :-

Last Answer : When a catalyst increases the rate of chemical reaction the rate constant :- A. Increases B. Decreases C. Remains constant D. Becomes infinite

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)

Description : The catalyst in a second order reversible reaction increases the rate of the forward reaction (A) And decreases that of backward reaction (B) And backward reaction equally (C) Only (D) To a greater extent than that of the backward reaction

Last Answer : (B) And backward reaction equally

Description : When a catalyst increases the rate of forward reaction, the value of rate constant (A) Increases (B) Decreases (C) Remain same (D) Becomes infinite

Last Answer : (A) Increases

Description : In a reversible reaction, a catalyst increases the rate of forward reaction (A) Only (B) To a greater extent than that of the backward reaction (C) And decreases that of the backward reaction (D) And the backward reaction equally

Last Answer : (D) And the backward reaction equally

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

Description : What purpose does FeCl3 serve in the electrophilic aromatic substitution reaction between chlorine and benzene? (a) It serves as a radical initiator to produce the chlorine radical needed to propagate the ... by reacting with the Cl2 and thereby activates it toward attack by benzene's π electrons.

Last Answer : It serves as a Lewis acid catalyst by reacting with the Cl2 and thereby activates it toward attack by benzene’s π electrons.

Description : When a catalyst increases the rate of chemical reaction, the rate constant (A) Decreases (B) Increases (C) Remain constant (D) Become infinite

Last Answer : (B) Increases

Description : Catalyst is a substance which (1) increases the rate of the reaction (2) decreases the rate of reaction (3) has no action on the rate of the reaction (4) None of these

Last Answer : None of these

Description : A catalyst is a substance which (a) stops a chemical reaction (b) helps initiate a reaction (c) increases the speed of a reaction (d) decreases the speed of a reaction

Last Answer : Ans:(c)

Description : A catalyst (a) Alters the velocity of a reaction (b) Increases the velocity of a reaction (c) Decreases the velocity of a reaction (d) Starts a reaction

Last Answer : Ans:(a)

Description : A catalyst in a chemical reaction __________ free energy change in the reaction. (A) Increases (B) Decreases (C) Either (A) or (B); depends on the type of catalyst (D) Neither (A) nor (B)

Last Answer : (C) Either (A) or (B); depends on the type of catalyst

Description : A Catalyst (A) Increases the equilibrium concentration of the product (B) Changes the equilibrium constant of the reaction (C) Shortens the time to reach the equilibrium (D) None of these

Last Answer : (C) Shortens the time to reach the equilibrium

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 : Promoter (A) Initiates a chemical reaction and is a catalyst by itself (B) Alters the position of equilibrium in a reversible reaction (C) Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals (D) All (A), (B) and (C)

Last Answer : (C) Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals

Description : 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)

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

Description : Catalyst is a substance, which __________ chemical reaction. (A) Increases the speed of a (B) Decreases the speed of a (C) Can either increase or decrease the speed of a (D) Alters the value of equilibrium constant in a reversible

Last Answer : (C) Can either increase or decrease the speed of a

Description : The equilibrium constant of a catalytic chemical reaction __________ due to the presence of a catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Last Answer : (C) Remain unaffected

Description : The equilibrium constant of chemical reaction __________ in the presence of catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Can either increase or decrease (depends on the type of catalyst)

Last Answer : (C) Remain unaffected

Description : Hydrogenation of edible vegetable oils (A) Is an exothermic reaction (B) Increases their melting point (C) Is done in presence of nickel catalyst (D) All (A), (B) and (C)

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

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 : (4) None of these Explanation: Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that ... may participate in multiple chemical transformations. Catalysts that speed the reaction are called positive catalysts.

Last Answer : Table salt gets moist during rainy season because – (1) sodium chloride is hygroscopic (2) sodium chloride is deliquescent (3) sodium chloride contains some quantity of sodium iodide (4) sodium chloride contains hygroscopic impurities like magnesium chloride

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

Description : In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for (A) Fast reactions in catalyst of small pore diameter (B) Fast reaction in catalyst ... reactions in catalyst of small pore diameter (D) Slow reactions in catalyst of large pore diameter

Last Answer : (C) Slow reactions in catalyst of small pore diameter

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 : A catalyst is said to be a negative catalyst, if it (A) Retards the rate of reaction (B) Reduces the value of equilibrium constant (C) Does not initiate the reaction (D) All (A), (B) and (C)

Last Answer : (A) Retards the rate of reaction

Description : Which of the following does not produce a change in the value of rate constant of a reaction? (A) Pressure (B) Temperature (C) Concentration and catalyst (D) None of these

Last Answer : (C) Concentration and catalyst

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 : Which of the following is not a unit of reaction rate? (A) Moles for med/(surface of catalyst) (time) (B) Moles formed/volume of reactor) (time) (C) Mole formed/volume of catalyst) (time) (D) None of these

Last Answer : (D) None of these

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 : Effectiveness factor (E) of a catalyst pellet is defined as, E = (actual rate within pore of the catalyst)/(rate if not snowed by pore diffusion), Effectiveness factor for a first order reaction is given by (where, T = Thiele modulus) (A) tan hT/T (B) tan T/T (C) tan hT/tan T (D) None of these

Last Answer : (A) tan hT/T

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.

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.

Description : A catalyst increases the

Last Answer : A catalyst increases the A. rate of forward reaction only B. free energy change in the ... reverse reactions D. equilibrium constant of the reaction.

Description : Pick out the correct statement pertaining to catalytic cracking. (A) With increase in the reactor pressure, octane number of gasoline decreases (B) With increase in the reactor temperature, gasoline yield decreases for a given ... with increase in the catalyst to oil ratio (D) All (A), (B) and (C)

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

Description : A substance which increases the efficiency of a catalyst is termed as: A. Promoter (Answer) B. Activator C. Retarder D. Super catalyst

Last Answer : A. Promoter (Answer)

Description : Considering the endothermic dissociation of CaCO3 in a closed vessel (CaCO3 ⇌ CaO + CO2 ), the pressure of CO2 increases, if (A) A catalyst is added (B) The temperature is increased (C) An inert gas is pumped keeping the temperature constant (D) None of these

Last Answer : (B) The temperature is increased

Description : Bulk diffusion in catalyst pore __________ with increase in pressure. (A) Increases (B) Decreases (C) Remains unchanged (D) Increases exponentially

Last Answer : (B) Decreases

Description : Assertion :- Catalyst change Gibbs free energy of system. Reason :- Catalyst changes preexponential factor of a chemical reaction.

Last Answer : Assertion :- Catalyst change Gibbs free energy of system. Reason :- Catalyst changes preexponential factor ... . If both Assertion & Reason are false.

Description : Assertion: Reaction of `SO_(2)` and `H_(2)S` in the presence of `Fe_(2)O_(3)` catalyst gives elemental sulphur. Reason: `SO_(2)` is a reducing agent.

Last Answer : Assertion: Reaction of `SO_(2)` and `H_(2)S` in the presence of `Fe_(2)O_(3)` catalyst gives ... is False. D. If both Assertion & Reason are False.

Description : Which of the following reaction parameters will change due to addition of a catalyst ?

Last Answer : Which of the following reaction parameters will change due to addition of a catalyst ? A. ... constant D. Both equilibrium constant and rate constant

Description : Why only small amount of enzyme is needed to catalyst a reaction involving many molecules?

Last Answer : Need answer

Description : How does an inhibitor slow down a reaction and a catalyst speed up a reaction?

Last Answer : A catalyst works by providing a reaction route with a loweractivation energy. An inhibitor slows a reaction and can work inseveral ways, for instance by tying up one of the reactants. ... when we say catalyst inhibitor, which issomething which binds to the active sites on a heterogeneouscatalyst.

Description : Why does catalyst affect reaction speed?

Last Answer : The activation energy is reduced.

Description : A catalyst remains unchanged at the end of the reaction with regard to (a) Quality (b) Chemical composition (c) Physical state (d) Quantity and chemical composition

Last Answer : Ans:(d)

Description : Polycondensation reaction of polymerisation (A) Does not produce linear polymers (B) Produces only thermoplastic material (C) Produces epoxy polymers (D) Does not need any catalyst

Last Answer : (C) Produces epoxy polymers

Description : Pick out the wrong statement. (A) Lower boiling paraffins have higher octane number than higher paraffins (B) Dehydrogenation of naphthenes to aromatics is a desirable reaction in reforming ... is dearomatised kerosene (D) Catalyst used in catalytic reforming is platinum on silica-alumina base

Last Answer : (C) The most ideal feedstock for thermal reforming is dearomatised kerosene

Description : The main purpose of recycling the byproduct hydrogen gas in the reformer reactor is to (A) Obviate catalyst poisoning (B) Maintain the reaction temperature (C) Sustain the reactor pressure (D) Hydrogenate the feed stock

Last Answer : (C) Sustain the reactor pressure

Description : Which is a catalyst promoter used in catalytic ammonia synthesis reaction? (A) Al2O3 (B) Cr2O3 (C) K2O (D) MnO

Last Answer : (C) K2O