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 : 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 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 : 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 : 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 : 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 : (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 : 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 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 : 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)
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 :-
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 increases rate of reaction by
Last Answer : A catalyst increases rate of reaction by A. Decreasing enthalpy B. Decreasing internal ... activation energy D. Increasing activation energy
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)
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 : 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 : What is the substance which decreases the rate of a chemical reaction? -Do You Know?
Last Answer : answer:
Description : What is the substance which decreases the rate of a chemical reaction?
Last Answer : Poison
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 : When an exothermic reversible reaction is conducted adiabatically, the rate of reaction (A) Continuously increases (B) Continuously decreases (C) Passes through a maximum (D) Passes through a minimum
Last Answer : (C) Passes through a maximum
Description : With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion). (A) Increases (B) Decreases (C) Remain same (D) Increases linearly
Description : As the chemical reaction proceeds, the rate of reaction (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease depending on the type of reaction
Description : 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
Last Answer : (B) Fraction of molecules having threshold energy increases
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 : 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)
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
Description : 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
Last Answer : (A) A catalyst does not change AH of the reaction
Description : Which of the following statements describes the effects of ambient temperature on local action within lead-acid storage batteries? A. Increasing ambient temperature increases local action. B. Increasing ambient ... has no effect on local action. D. At 90°F all local action virtually ceases.
Last Answer : Answer: A
Description : With the increase of pressure, the boiling point of any substance - (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero
Last Answer : (1) Increases Explanation: The temperature stays the same until all the liquid has vaporized. As the temperature of a liquid rises, the pressure of escaping vapor also rises, and at the boiling point ... vapor is equal to that exerted on the liquid by the surrounding air, causing bubbles to form.
Description : With the increase of pressure, the boiling point of any substance – (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero
Description : With increase in porosity, the thermal conductivity of a solid substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the solid
Description : With increase in temperature, the internal energy of a substance (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance
Description : If we increase the pressure on a substance (which is at its triple point), then the triple point (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the substance
Last Answer : (C) Remains unchanged
Description : When a solid melts, a. the temperature of the substance increases. b. the temperature of the substance decreases. c. heat leaves the substance. d. heat enters the substance.
Last Answer : heat enters the substance.
Description : Benzene reacts with H2 at 150°C at 30 atm in the presence of Ni catalyst to give (a) Cyclohexane (b) Cyclohexene (c) n-Hexane (d) No reaction occurs
Last Answer : Cyclohexane
Description : Action of insulin on lipid metabolism is (A) It increases lipolysis and increases triglyceride synthesis (B) It decreases lipolysis and increases triglyceride synthesis (C) It decreases ... and decreases triglyceride synthesis (D) It increases synthesis of triglyceride and increased ketogenesis
Last Answer : Answer : B
Description : Which of the following represents the action of insulin? (a) Increases blood glucose level by stimulating glucagon production. (b) Decreases blood glucose levels by forming glycogen. (c) ... promoting cellular uptake of glucose. (d) Increases blood glucose levels by hydrolysis of glycogen.
Last Answer : (b) Decreases blood glucose levels by forming glycogen
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 : 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 BrunauerEmmett-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 : A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A ... (D) Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1
Last Answer : (A) Inner catalyst core of radius R/8 does not participate in reaction (
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