0% 0 Chemical Reaction Quiz 5 1 / 50 Pick out the wrong statement ? For the same conversion, the holding time required in a batch reactor, is always equal to the space time required in a PFR Two mixed reactors of unequal size are available for producing a specified product, formed by a homogenous second order reaction. To achieve maximum production rate, the smaller reactor should be placed in series before the larger reactor The mechanism for the decomposition of CH3CHO into CH4 and CO in presence of I2 is: CH3CHO + I2 ? CH3I + HI + CO; slow CH3I + HI ? CH4 + I2; fast Then the rate of disappearance of CH3CHO is equal to K.CCH3I.CHI and acts as a catalyst Arrhenius equation describing the effect of temperature on rate constant is given by, choiceno A K = A.e-Ea/RT 2 / 50 Kinetics of a solid catalysed reaction can best be studied in a __________ reactor? Plug-flow Mixed Batch None of these 3 / 50 Pick out the wrong statement ? A catalyst remains unchanged in chemical composition at the end the reaction A catalyst initiates a reaction A catalyst is specific in reaction A catalyst does not alter the final position of equilibrium in a reversible reaction 4 / 50 Inversion of cane sugar is an example of ________? Unimolecular reaction with first order Bimolecular reaction with second order Bimolecular reaction with first order Unimolecular reaction with second order 5 / 50 Pick out the correct statement ? The composition of equilibrium is changed by catalyst Pressure changes do not change the equilibrium concentrations A catalyst speeds up the forward reaction but slows shown the reverse reaction Addition of catalyst changes the equilibrium constant 6 / 50 Pick out the wrong statement ? Space time in a flow reactor is a measure of its capacity and is equal to the residence time when the density of reaction mixture is constant Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty In an ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively 7 / 50 Molecularity of an elementary reaction, P + Q ? R + S is ______? 3 1 4 2 8 / 50 Pick out the correct statement ? Chemical equilibrium state is dynamic in nature A chemical reaction accompanied by absorption of heat is called an exothermic reaction The rate constant for a first order reaction does not change on changing the concentration units A chemical reaction accompanied by evolution of heat is called an endothermic reaction 9 / 50 Kinetics of a catalytic reaction can be best studied on a/an _______ reactor? Mixed Either A., B. and C. Differential (flow) Integral (plug flow) 10 / 50 Photochemical reaction rate does not depend significantly on temperature, because______? None of these The energy of reacting molecules exceeds the activation energy by absorption of light It is an exothermic reaction It is a reversible reaction 11 / 50 In the fluid catalytic cracker (FCC), the cracking reaction is ______ (i) and the regeneration is ________ (ii) ________? (i) endothermic (ii) exothermic (i) endothermic (ii) endothermic (i) exothermic (ii) exothermic (i) exothermic (ii) endothermic 12 / 50 Molecularity of a reaction___________? Is always equal to the overall order of reaction May not be equal to the order of reaction Can?t have a fractional value Both B. and C. 13 / 50 Ionic reactions occur in______? Solutions Any state Liquid state only Solid state only 14 / 50 In which of the following gaseous phase reversible reactions, the product yield cannot be increased by the application of high pressure ? 2SO2 + O2 ? 2SO3 N + 3H2 ? 2NH3 N2 + O2 ? 2NO PCl3 + Cl2 ? PCl5 15 / 50 In chamber process of sulphuric acid manufacture in industry, the gas phase oxidation of SO2 to SO3 is accomplished by a _______ reaction ? Non-catalytic homogeneous Catalytic heterogeneous Catalytic homogenous Non-catalytic heterogeneous 16 / 50 Maximum equilibrium conversion for endothermic reaction is obtained at the _______ temperature? Room Highest possible Intermediate Lowest possible 17 / 50 Pick out the correct statement? A catalyst initiates a chemical reaction In catalytic reactions, the catalyst reacts with the reactants A catalyst lowers the activation energy of the reacting molecules A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction 18 / 50 In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for_________? Fast reaction in catalyst of large pore diameter Fast reactions in catalyst of small pore diameter Slow reactions in catalyst of small pore diameter Slow reactions in catalyst of large pore diameter 19 / 50 In the hydrodealkylation of toluene to benzene, the following reactions occur: C7H8 + H2 ? C6H6 + CH4 2C6H6 ? C12H10 + H2 Toluene and hydrogen are fed to a reactor in a molar ratio 1:5.80% of the toluene gets converted and the selectivity of benzene(defined as moles of benzene formed/moles of toluene converted) is 90%. The fractional conversion of hydrogen is_________? 0.152 0.16 0.136 0.144 20 / 50 Mean residence time is equal to the space time, when__________? All A., B. and C. The temperature, pressure and the density of reaction mixture remains constant throughout the reactor There is no change in number of moles in gaseous reaction The feed rate is measured at temperature and pressure in the reactor 21 / 50 In which of the following reactions, the equilibrium will shift to the right, if the total pressure is increased ? N2O4 ? 2 NO2 H2 + I2 ? 2HI N2 + O2 ? 2NO H2 + Cl2 ? 2HCl 22 / 50 Pick out the correct statement? A lower temperature favours the reaction of lower activation energy Pore volume and porosity of a catalyst is measured by Brunauer-Emmett-Teller (BET) technique The dispersion number for a reactor/vessel is uL/D The rate controlling step in a reaction involving many steps is the fastest step 23 / 50 Most important characteristics of gas-liquid reactors are the_________? None of these Both A. and B. Liquid hold-up Specific inter-facial area 24 / 50 Pick out the wrong statement ? In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system In a semi-batch reactor, one reactant is charged batch wise, while the other reactant is fed continuously In a continuous flow reactor, both the reactants and the products flow out continuously 25 / 50 Pick out the wrong statement ? For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity For an ideal mixed reactor at steady state, the exit stream has the same composition as fluid within the reactor and the space time is equivalent to holding time for constant density system Plug flow reactor (PFR) is always smaller than mixed reactor for all positive reaction orders for a particular duty Reaction rate does not decrease appreciably as the reaction proceeds in case of an autocatalytic reaction 26 / 50 Limiting reactant in a chemical reaction decides the______? Conversion Reaction speed Rate constant Equilibrium constant 27 / 50 Integral method for analysing the kinetic data is used _______? None of these When the data are scattered Both A. and B. For testing specific mechanisms with simple rate expressions 28 / 50 Pick out the wrong statement pertaining to space velocity of flow reactors? The space velocity of 3 hr-1 means that three reactor volumes of feed at specified conditions are being fed into the reactor every hour None of these The space velocity of 3 hr-1 means that one third reactor volume of feed at specified conditions are being fed into the reactor The unit of space velocity is (time)-1 29 / 50 Pick out the correct statement? Reactions with high activation energies are very temperature sensitive Chemical equilibrium is a static state A chemical reaction occurs when the energy of the reacting molecule is less than the activation energy of the reaction A photochemical reaction is catalysed by light 30 / 50 In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is_____? Same Less More Either A. or B., depends on other factors 31 / 50 Pick out the wrong statement ? A flat velocity profile exists in a plug flow reactor Half life of a reaction increases with increased initial concentration for reaction orders more than one Chemical reactions with high activation energy are very temperature sensitive The residence time for all the elements of fluid in case of a P.F.R. need not be same 32 / 50 Pick out the wrong statement ? Study of non-ideal flow reactor is done experimentally by stimulus-response technique ?Hold back? is defined as the fraction of material that stays longer than the mean residence time For studying a chemical reaction, it is desirable to monitor the reactants during initial stages and the products during the final stages of reaction A batch reactor cannot be used to study the kinetics of catalytic reaction 33 / 50 Pick out the wrong statement ? Molecularity of a reaction cannot be zero but the order of a reaction can be zero Slow chemical reactions have generally high values of activation energy In general, the rate of a reaction becomes triple for every 10?C rise in temperature In a multistep reaction, the slowest step is the rate determining step 34 / 50 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 catalyst, if it does not entail a chain mechanism? Proportional to Inversely proportional to Proportional to the square of Independent of 35 / 50 On application of pressure to the equilibrium system, ice ? water; which of the following phenomenon will occur ? Equilibrium will not be attained More water will be formed Water will evaporate More ice will be formed 36 / 50 Organic catalysts differ from the inorganic catalyst in the sense that the former is_________? Prohibitively costly Proteinous in nature Active at very high temperature only Active at cryogenic temperatures only 37 / 50 Pick out the wrong statement ? For a second order reaction, the slope of the graph/plot between rate and (concentration) is equal to the rate constant (k) Molecularity of the reaction is always a whole number greater than zero Visible radiation provides the necessary activation energy in photochemical reactions The order and molecularity of a complex reaction may not be the same 38 / 50 Knudsen diffusion is directly proportional to _______? T T2 ?T 1/?T 39 / 50 In which of the following gaseous phase reactions, the equilibrium of the reaction remains unaffected by pressure changes ? N2 + O2 ? 2NO 2NO2 ? N2O4 2O3 ? 3O2 2SO2 + O2 ? 2SO3 40 / 50 Non-catalytic fluid-solid reactions are represented by ________ model? Neither A. and B. Both A. and B. Unreacted core Continuous reaction 41 / 50 Pick out the correct statement ? A catalyst does not change AH of the reaction Law of mass action was suggested by Le-Chatelier A catalyst changes the equilibrium point The difference between the energy of reactants and that of the products is the activation energy 42 / 50 Pick out the wrong statement ? The fractional conversion at any time is same for both the constant as well as the variable volume system in case of an irreversible unimolecular type first order reaction Autocatalytic reactions are exemplified by microbial fermentation reactions Hydrolysis of ester in presence of alkali or acid is a zero order reaction The slowest step has the greatest influence on the overall reaction rate in case of an irreversible series reaction 43 / 50 In Langmuir treatment of adsorption,__________? Whole surface of the catalyst is essentially uniform and the adsorbed molecule has no effect on the rate of adsorption per site All the adsorption does not take place by the same mechanism Whole surface of the catalyst does not have the same activity for adsorption and there is attraction between the adsorbed molecule Extent of adsorption is more than one complete monomolecular layer on the surface 44 / 50 In the converter of the contact process for the manufacture of H2SO4 the equilibrium conversion of SO2__________ (i) __________ with increase in temperature and __________ (ii) __________ with increase in the mole ratio of SO2 to air? (i) decreases (ii) decreases (i) increases (ii) decreases (i) decreases (ii) increases (i) increases (ii) increases 45 / 50 Oil is hydrogenated using nickel catalyst in a ___________ reactor? Fluidised bed Fixed bed Slurry Batch 46 / 50 Participation of ________ is involved in the occurrence of a chemical reaction? Protons None of these Electrons Neutrons 47 / 50 Photo-chemical reactions occur in presence of _____? Darkness Monochromatic radiation only Solid catalysts Sunlight 48 / 50 In the reversible reaction of the type, A + B ? AB, in general___________? Neither of the reactions will be endothermic The combination reaction will be endothermic, while the dissociation reaction will be exothermic The combination reaction will be exothermic, while the dissociation reaction will be endothermic Both forward and backward reactions will be exothermic 49 / 50 In flow reactors, the performance equations interrelate the rate of reaction to the_____? Reactor volume Feed rate Extent of reaction All A., B. and C. 50 / 50 In the gaseous phase ammonia formation reaction (N2 + 3H2 ? 2NH3), the value of the equilibrium constant depends on the__________? Total pressure of the system Volume of the reactor Temperature Initial concentration of N2 and H2 Provide Your Information Your score is The average score is 0% LinkedIn Facebook Twitter 0% Restart quiz Send feedback Share on facebook Facebook Share on twitter Twitter Share on whatsapp WhatsApp PrevChemical Reaction Quiz 4 Chemical Reaction Quiz 6Next
