MCQOPTIONS
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MCQOPTIONS
This section includes 1443 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 901. |
The time needed to achieve the same fractional conversion for particles of different sizes (d) when chemical reaction controls, is proportional to |
| A. | d |
| B. | d |
| C. | d1.5 |
| D. | d2 |
| Answer» B. d | |
| 902. |
In case of __________ reactions, the reaction rate does not decrease appreciably as the reaction proceeds. |
| A. | catalytic |
| B. | parallel |
| C. | series |
| D. | auto catalytic |
| Answer» E. | |
| 903. |
An irreversible aqueous phase reaction, A + B P, is carried out in an adiabatic mixed flow reactor. A feed containing 4kmole/m3 of each A and B enters the reactor at 8m3 /hr. If the temperature of the exit stream is never to exceed 390 K, what is the maximum inlet feed temperature allowed?Data: Heat of reaction = - 50 kJ/moleDensity of the reacting mixture = 1000kg/m3Specific heat of reacting mixture = 2kJ/kg.K The above data can be assumed to be independent of temperature and composition. |
| A. | 190 |
| B. | 290 |
| C. | 390 |
| D. | 490 |
| Answer» C. 390 | |
| 904. |
In case of calcination of limestone, CaCO3 CaO + CO2, the addition of more of CaO will result in __________ in the concentration of CO2. |
| A. | no change |
| B. | increase |
| C. | decrease |
| D. | unpredictable from the data |
| Answer» B. increase | |
| 905. |
If helium is introduced in a reactor containing O2, SO2 and SO3 at equilibrium, so that total pressure increases while volume and temperature remains constant. In this case the dissociation of SO3 (as per Le Chatlier principle) |
| A. | decreases |
| B. | increases |
| C. | remains unaltered |
| D. | changes unpredictably. |
| Answer» B. increases | |
| 906. |
In case of staged packed bed reactors carrying out exothermic reaction, use |
| A. | high recycle for pure gas. |
| B. | plug flow for dilute liquid requiring no large preheating of feed. |
| C. | cold shot operations for a dilute solution requiring large preheating to bring the stream upto the reaction temperature. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 907. |
A catalyst is said to be a negative catalyst, ifit |
| 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). |
| Answer» B. reduces the value of equilibrium constant. | |
| 908. |
The rate expression for the gaseous phase reaction, CO + 2H2 CH3OH, is given by, . Which of the following is not possible ? |
| A. | α = 1, β = 1, γ =1 |
| B. | α = 1, β = 2, γ = 1 |
| C. | α = 1/3, β = 2/3, γ = 1/3 |
| D. | α = 1/2, β = 1, γ = 1/2 |
| Answer» B. Œ± = 1, Œ≤ = 2, Œ≥ = 1 | |
| 909. |
In case of a consecutive unimolecular type first order reaction , the concentration of component __________ increases continuously with time. |
| A. | S |
| B. | R |
| C. | A |
| D. | none of these |
| Answer» B. R | |
| 910. |
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. |
| Answer» D. None of these. | |
| 911. |
Which of the following is a characteristic of an ideal plug flow reactor ? |
| A. | Axial dispersion |
| B. | Flat velocity profile |
| C. | Uniform mixing |
| D. | None of these |
| Answer» C. Uniform mixing | |
| 912. |
Conversion increases with increase in temperature in case of a an __________ reaction. |
| A. | autocatalytic |
| B. | irreversible |
| C. | reversible endothermic |
| D. | reversible exothermic |
| Answer» D. reversible exothermic | |
| 913. |
The optimum performance for reactors operating in parallel is obtained when the feed stream is distributed in such a way, that the |
| A. | space time for each parallel line is same. |
| B. | space time for parallel lines is different. |
| C. | larger reactors have more space time compared to smaller ones. |
| D. | none of these. |
| Answer» B. space time for parallel lines is different. | |
| 914. |
Signal normally used to study non-ideal flow by stimulus response technique is __________ input. |
| A. | pulse |
| B. | step |
| C. | both (a) & (b) |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 915. |
For a tubular flow reactor with uniform concentration and temperature, the independent variable is |
| A. | time |
| B. | length |
| C. | diameter |
| D. | none of these |
| Answer» C. diameter | |
| 916. |
The reaction A B is conducted in an isothermal batch reactor. If the conversion of A increases linearly with holding time, then the order of the reaction is |
| A. | 0 |
| B. | 1 |
| C. | 1.5 |
| D. | 2 |
| Answer» B. 1 | |
| 917. |
Participation of __________ is involved in the occurrence of a chemical reaction. |
| A. | protons |
| B. | neutrons |
| C. | electrons |
| D. | none of these |
| Answer» D. none of these | |
| 918. |
Maximum equilibrium conversion for endothermic reaction is obtained at the __________ temperature. |
| A. | highest possible |
| B. | lowest possible |
| C. | intermediate |
| D. | room |
| Answer» B. lowest possible | |
| 919. |
The decomposition of A into B is represented by the exothermic reaction, A 2B. To achieve maximum decomposition, it is desirable to carry out the reaction. |
| A. | at high P and high T. |
| B. | at low P and high T. |
| C. | at low P and low T. |
| D. | at high P and low T. |
| Answer» D. at high P and low T. | |
| 920. |
In case of a __________ reactor, the composition in the reactor and at the exit of the reactor is the same. |
| A. | semi-batch |
| B. | tubular |
| C. | batch |
| D. | back-mix |
| Answer» E. | |
| 921. |
The sequence in which three CSTR's of volumes 5, 10 and 15 m3 will be connected in series to obtain the maximum production in a second order irreversible reaction is |
| A. | 15, 10, 5 |
| B. | 5, 10, 15 |
| C. | 10, 5, 15 |
| D. | 10, 15, 5 |
| Answer» B. 5, 10, 15 | |
| 922. |
When the reaction is dominated by in-traparticle diffusion, the apparent order of reaction (nD) as measured is related to the true order (n) as |
| A. | |
| B. | |
| Answer» B. | |
| 923. |
Carbon particles accummulated on the catalyst used in the gas oil cracking lies in the category of __________ poison. |
| A. | deposited |
| B. | chemisorbed |
| C. | selectivity |
| D. | stability |
| Answer» B. chemisorbed | |
| 924. |
If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the __________ diffusion. |
| A. | film |
| B. | ash layer |
| C. | pore |
| D. | none of these |
| Answer» B. ash layer | |
| 925. |
Which of the following chemical reactions will be favoured by low pressure ? |
| A. | 2HI H2 + I2 |
| B. | N2O2 2NO2 |
| C. | N2 + O2 2NO |
| D. | none of these |
| Answer» C. N2 + O2 2NO | |
| 926. |
For a heterogenous catalytic reaction, A + B C, with equimole feed of A and B, the initial rate - rA0 is invariant with total pressure. The rate controlling step is |
| A. | surface Kc/(1 + TS) reaction between absorbed A and B in the gas phase. |
| B. | surface reaction between absorbed A and absorbed B. |
| C. | surface reaction between A in the gas phase and absorbed B. |
| D. | desorption of C. |
| Answer» E. | |
| 927. |
Half-life period for a first order reaction is __________ the initial concentration of the reactant. |
| A. | directly proportional to |
| B. | inversely proportional to |
| C. | independent of |
| D. | none of these |
| Answer» D. none of these | |
| 928. |
Considering the endotheomic 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. |
| Answer» C. an inert gas is pumped keeping the temperature constant. | |
| 929. |
Half life period of a first order irreversible reaction A B is |
| A. | k/2 |
| B. | ln k/2 |
| C. | ln 2/k |
| D. | ln 0.5/k |
| Answer» D. ln 0.5/k | |
| 930. |
The irreversible reaction, X Y, is the special case of the reversible reaction, X Y, in which the |
| A. | equilibrium constant is infinite. |
| B. | fractional conversion of 'A' at equilibrium is unity. |
| C. | concentration of 'A' at equilibrium is zero. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 931. |
If 'n' is the order of reaction, then unit of rate constant is |
| A. | 1/(time)(concentration)n - 1 |
| B. | (time)-1 (concentration)n - 1 |
| C. | (time)n - 1 (concentration) |
| D. | none of these |
| Answer» B. (time)-1 (concentration)n - 1 | |
| 932. |
Volume change for unimolecular type first order reaction , increases __________ with time. |
| A. | linearly |
| B. | exponentially |
| C. | parabolically |
| D. | logarithmically |
| Answer» C. parabolically | |
| 933. |
A liquid decomposes by irreversible first order kinetics and the half life period of this reaction is 8 minutes. The time required for 75% conversion of the liquid will be __________ minutes. |
| A. | 4 |
| B. | 8 |
| C. | 12 |
| D. | 16 |
| Answer» E. | |
| 934. |
When all the limiting reactant is consumed in the reaction, the operational yield __________ the relative yield. |
| A. | is greater than |
| B. | is smaller than |
| C. | equals |
| D. | can be either greater or smaller than (depends on the type of reaction) |
| Answer» D. can be either greater or smaller than (depends on the type of reaction) | |
| 935. |
The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is __________ that of mixed reactor. |
| A. | greater than |
| B. | equal to |
| C. | smaller than |
| D. | unpredictable from the data |
| Answer» D. unpredictable from the data | |
| 936. |
A reaction in which one of the products of reaction acts as a catalyst is called a/an __________ reaction. |
| A. | catalytic |
| B. | autocatalytic |
| C. | photochemical |
| D. | none of these |
| Answer» C. photochemical | |
| 937. |
Which of the following curves shows the effect of temperature on the extent of gas-solid adsorption at a given pressure ? |
| A. | Langmuir adsorption isotherm |
| B. | Adsorption isobar |
| C. | Freundlich adsorption isotherm |
| D. | None of these |
| Answer» C. Freundlich adsorption isotherm | |
| 938. |
Which of the following is the most suitable for isothermal operation ? |
| A. | Batch reactor |
| B. | Back-mix reactor |
| C. | Plug-flow reactor |
| D. | Fixed bed reactor |
| Answer» C. Plug-flow reactor | |
| 939. |
For the reaction , the rate of formation of Z is 0.2 gm mole/litre.hr. what is the rate of disappearance of X in gm mole/litre. hr ? |
| A. | 0.4 |
| B. | 0.1 |
| C. | 0.2 |
| D. | none ofthese |
| Answer» B. 0.1 | |
| 940. |
Oil is hydrogenated using nickel catalyst in a __________ reactor. |
| A. | batch |
| B. | slurry |
| C. | fluidised bed |
| D. | fixed bed |
| Answer» C. fluidised bed | |
| 941. |
6 gm of carbon is burnt with an amount of air containing 18 gm oxygen. The product contains 16.5 gms CO2 and 2.8 gms CO besides other constituents. What is the degree of conversion on the basis of disappearance of limiting reactant ? |
| A. | 1 |
| B. | 0.95 |
| C. | 0.75 |
| D. | 0.2 |
| Answer» C. 0.75 | |
| 942. |
Carrier in a catalyst increases its |
| A. | surface area |
| B. | activity |
| C. | performance |
| D. | none of these |
| Answer» B. activity | |
| 943. |
'If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the |
| A. | pressure |
| B. | temperature |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» C. both (a) & (b) | |
| 944. |
Exposure of a photographic plate to produce a latent image is an example of __________ reaction. |
| A. | very slow |
| B. | very fast |
| C. | photochemical |
| D. | both (b) and (c) |
| Answer» E. | |
| 945. |
The order of the chemical reaction, , whose rate equation is given as -rA = KCA2. CB is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» E. | |
| 946. |
The rate of a chemical reaction is almost doubled for every 10°C rise in temperature. The rate will increase __________ times, if the temperature rises form 10 to 100°C.$ |
| A. | 256 |
| B. | 512 |
| C. | 112 |
| D. | 612 |
| Answer» C. 112 | |
| 947. |
For a reaction of the type, , the rate of reaction (- rx) is given by |
| A. | (K1+K1)CX |
| B. | (K1+K2+K3)CX |
| C. | K1CV - K2CX |
| D. | (K1-K2)CX |
| Answer» D. (K1-K2)CX | |
| 948. |
For high conversion in a highly exothermic solid catalysed reaction, use a __________ bed reactor. |
| A. | fixed |
| B. | fluidised bed reactor followed by a fixed |
| C. | fixed bed reactor followed by a fluidised |
| D. | fluidised |
| Answer» C. fixed bed reactor followed by a fluidised | |
| 949. |
The first order series reaction is conducted in a batch reactor. The initial concentrations of A, B and C (CA0, CB0, CC0 respectively) are all non-zero. The variation of CB with reaction time will not show a maximum, if |
| A. | k2 CB0 > k1 CA0 |
| B. | k CA0 > k2.CB0 |
| C. | CB0 > CA0 |
| D. | CA0 > CB0 |
| Answer» B. k CA0 > k2.CB0 | |
| 950. |
__________ gas is normally employed in B.E.T.method of finding out the surface area of catalyst. |
| A. | N2 |
| B. | H2 |
| C. | CO2 |
| D. | He |
| Answer» B. H2 | |