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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 4901. |
For the non catalytic reaction of particles with surrounding fluid, the same needed to achive the same fractional conversion for particles of different unchanging sizes is proportional to the particle diameter, when the __________ is the controlling resistance. |
| A. | film diffusion |
| B. | diffusion through ash layer |
| C. | chemical reaction |
| D. | either (a), (b) or (c) |
| Answer» D. either (a), (b) or (c) | |
| 4902. |
Pure ethanol vapor is fed to a reactor packed with alumina catalyst, at the rate of 100 kmole / hr. The reactor products comprise: ethylene :95 kmole / hr, water vapour: 97.5 k mole / hr and diethyl ether :2.5 kmole/hr. The reactions occuring can be represented by:C2H5OH C2H4 + H2O2C2H5OH C2H5 - O - C2H5 + H2OThe percent conversion of ethanol in the reactor is |
| A. | 100 |
| B. | 97.5 |
| C. | 95 |
| D. | 2.5 |
| Answer» B. 97.5 | |
| 4903. |
A backmix reactor |
| A. | is same as plug-flow reactor. |
| B. | is same as ideal stirred tank reactor. |
| C. | employs mixing in axial direction only. |
| D. | is most suitable for gas phase reaction. |
| Answer» C. employs mixing in axial direction only. | |
| 4904. |
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 |
| Answer» E. | |
| 4905. |
In a chemical reaction , it is observed that the (i) rate of formation of 'P' is doubled on doubling the concentration of 'X'. (ii) rate of formation of 'P' is quadrupled on doubling the concentration of 'Y'. (iii) doubling the concentration of 'Z' does not affect the rate of formation of 'P'. What is the order of the above chemical reaction? |
| A. | Zeroth order |
| B. | First order |
| C. | Second order |
| D. | Third order |
| Answer» E. | |
| 4906. |
Half life period of a chemical reaction is |
| A. | the time required to reduce the concentration of the reacting substance to half its initial value. |
| B. | half of the space time of a reaction. |
| C. | half of the residence time of a reaction. |
| D. | none of these |
| Answer» B. half of the space time of a reaction. | |
| 4907. |
Helium-mercury method is used for the measurement of the __________ of the catalyst. |
| A. | surface area |
| B. | porosity |
| C. | pore volume |
| D. | both (b) & (c). |
| Answer» E. | |
| 4908. |
What is the order of a chemical reaction whose rate is deter-mined by the variation of one concentration term only ? |
| A. | zero |
| B. | first |
| C. | second |
| D. | third |
| Answer» C. second | |
| 4909. |
The reaction in which one of the products of reaction acts as a catalyst is called a/an __________ reaction. |
| A. | biochemical |
| B. | photochemical |
| C. | catalytic |
| D. | autocatalytic |
| Answer» E. | |
| 4910. |
A typical example of an exothermic reversible reaction conducted at high pressure in industry is |
| A. | dehydration of ethanol. |
| B. | methanol synthesis. |
| C. | reformation of methane. |
| D. | polymerisation of ethylene. |
| Answer» B. methanol synthesis. | |
| 4911. |
Study of chemical kinetics is the easiest in the case of __________ reactions. |
| A. | irreversible |
| B. | reversible |
| C. | surface |
| D. | side |
| Answer» B. reversible | |
| 4912. |
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. |
| Answer» C. catalysts have very high selectivity. | |
| 4913. |
Semibatch reactor is preferred, when a/an |
| A. | a highly exothermic reaction is to be controlled. |
| B. | undersirable 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). |
| Answer» E. | |
| 4914. |
The rate constant of a first order reaction depends on the |
| A. | concentration of the reactant. |
| B. | temperature. |
| C. | concentration of the product. |
| D. | time. |
| Answer» C. concentration of the product. | |
| 4915. |
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 | |
| 4916. |
The ratio of volume of mixed reactor to the volume of P.F.R. (for identical flow rate, feed composition and conversion) for zero order reaction is |
| A. | |
| B. | 0 |
| C. | 1 |
| D. | > 1 |
| Answer» D. > 1 | |
| 4917. |
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. |
| Answer» C. Removal of at least one of the products at regular interval. | |
| 4918. |
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 | |
| 4919. |
Which of the following resistances is not involved in a gas phase catalytic (gas-solid) reaction ? |
| A. | Ash resistance. |
| B. | Gas film and pore surface diffusion resistances for reactants. |
| C. | Surface phenomenon resistance. |
| D. | Gas film and pore surface diffusion resistances for products. |
| Answer» B. Gas film and pore surface diffusion resistances for reactants. | |
| 4920. |
If the time required to change the concentration of reactant to half its original value is independent of the initial concentration, the order of reaction is |
| A. | zero |
| B. | one |
| C. | two |
| D. | three |
| Answer» C. two | |
| 4921. |
A batch adiabatic reactor at an initial temperature of 373 K is being used for the reaction, A B. Assume the heat of reaction is - 1kJ/mole at 373 K and heat capacity of both A and B to be constant and equal to 50J/mole.K. The temperature rise after a conversion of 0.5 will be |
| A. | 5 C |
| B. | 10 C |
| C. | 20 C |
| D. | 100 C |
| Answer» C. 20 C | |
| 4922. |
A photochemical reaction is |
| A. | accompanied with emission of light. |
| B. | catalysed by light. |
| C. | initiated by light. |
| D. | all (a), (b) & (c). |
| Answer» D. all (a), (b) & (c). | |
| 4923. |
Space velocity |
| A. | describes the extensive operating characteristics of a tubular flow reactor. |
| B. | is the maximum feed rate pre unit volume of reactor for a given conversion. |
| C. | is a measure of the ease of the reaction. |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 4924. |
A reaction which is catalysed by a base is catalysed by all substances which have a tendency to |
| A. | lose a proton |
| B. | gain a proton |
| C. | gain an electron |
| D. | none of these |
| Answer» C. gain an electron | |
| 4925. |
The fractional volume change between no conversion and complete conversion, for the isothermal gas phase reaction, 2A R, is |
| A. | 0.5 |
| B. | -0.5 |
| C. | 1 |
| D. | 1.5 |
| Answer» C. 1 | |
| 4926. |
When the density of the reaction mixture is constant in a chemical reaction, the ratio of the mean residence time to space time is |
| A. | > 1 |
| B. | < 1 |
| C. | 1 |
| D. | 0 |
| Answer» D. 0 | |
| 4927. |
In an ideal tubular-flow reactor |
| A. | there is no mixing in longitudinal direction. |
| B. | mixing takes place in radial direction. |
| C. | there is a uniform velocity across the radius. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 4928. |
At a given value of E/R (ratio of activation energy and gas constant), the ratio of the rate constants at 500 K and 400 K is 2, if Arrhenious law is used. What will be this ratio, if transition state theory is used with the same value of E/R? |
| A. | 1.6 |
| B. | 2 |
| C. | 2.24 |
| D. | 2.5 |
| Answer» E. | |
| 4929. |
__________ is the controlling step in a highly temperature sensitive fluid-solid non-catalytic reaction. |
| A. | Gas film diffusion |
| B. | Ash diffusion |
| C. | Chemical reaction |
| D. | none of these |
| Answer» D. none of these | |
| 4930. |
Foul odour and bad taste of water is removed by treating with |
| A. | alum |
| B. | bleaching powder |
| C. | activated carbon |
| D. | copper sulphate. |
| Answer» D. copper sulphate. | |
| 4931. |
Removal of __________ results from the disinfection of water. |
| A. | turbidity |
| B. | odour |
| C. | hardness |
| D. | bacteria |
| Answer» E. | |
| 4932. |
Carcinogenic air pollutants cause |
| A. | bone decay |
| B. | cancer |
| C. | asphyxiation (suffocation) |
| D. | anemia |
| Answer» C. asphyxiation (suffocation) | |
| 4933. |
Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundaries causes |
| A. | asphyxiation (suffocation). |
| B. | shortness of breath. |
| C. | tuberculosis. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 4934. |
Soluble silica present in boiler feed water can be removed by |
| A. | coagulation |
| B. | filtration |
| C. | anion exchanger |
| D. | preheating it |
| Answer» D. preheating it | |
| 4935. |
Out of the following, TLV of __________ is maximum (about 500 ppm). |
| A. | carbon dioxide |
| B. | toluene |
| C. | carbon disulphide |
| D. | acetaldehyde |
| Answer» B. toluene | |
| 4936. |
Which of the following plants does not emit appreciable amount of SO2 in atmosphere ? |
| A. | Thermal power plant |
| B. | Petroleum refinery |
| C. | Nitric acid plant |
| D. | Sulphuric acid plant |
| Answer» D. Sulphuric acid plant | |
| 4937. |
The maximum CO2 is emitted into the atmosphere by |
| A. | combustion |
| B. | urea |
| C. | biomass burning |
| D. | trees |
| Answer» B. urea | |
| 4938. |
Presence of volatile compounds like gasoline, oil, alcohol, ether etc. in municipal sewers may cause |
| A. | explosion |
| B. | non biodegradable foam |
| C. | undesirable plant growth |
| D. | corrosion |
| Answer» B. non biodegradable foam | |
| 4939. |
Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan |
| A. | with greater number of blades. |
| B. | of increased diameter. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 4940. |
Presence of soluble organics in polluted water causes |
| A. | undesirable plants growth. |
| B. | depletion of oxygen. |
| C. | fire hazards. |
| D. | explosion hazards. |
| Answer» C. fire hazards. | |
| 4941. |
Exposure to chemicals having carcinogenic properties cause |
| A. | dermatitis (skin disorder) |
| B. | cancer |
| C. | asphyxiation |
| D. | asthma |
| Answer» C. asphyxiation | |
| 4942. |
Presence of __________ in water stream are deleterious to aquatic life. |
| A. | soluble and toxic organics. |
| B. | suspended solids. |
| C. | heavy metals and cynides. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 4943. |
Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds __________ percent (by volume). |
| A. | 1 |
| B. | 3 |
| C. | 7 |
| D. | 20 |
| Answer» E. | |
| 4944. |
Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels. |
| A. | 75 |
| B. | 95 |
| C. | 120 |
| D. | 140 |
| Answer» C. 120 | |
| 4945. |
__________ can not control the noise pollution. |
| A. | Use of silencers |
| B. | Green house gases |
| C. | Vibration damping |
| D. | Tree plantation |
| Answer» C. Vibration damping | |
| 4946. |
Ozone level is generally found to be depleted in India in the month of |
| A. | February |
| B. | July |
| C. | April |
| D. | December |
| Answer» E. | |
| 4947. |
Noise level during normal conversation among men is about __________ decibles. |
| A. | 10 |
| B. | 45 |
| C. | 90 |
| D. | 115 |
| Answer» C. 90 | |
| 4948. |
'Particulate' air pollutants are finely divided solids and liquids. Which of the following is not a 'particulate' ? |
| A. | Dust & mists |
| B. | Smoke & fumes |
| C. | Photochemical smog & soot |
| D. | None of these |
| Answer» E. | |
| 4949. |
A shallow pond in which the sewage is retained and biologically treated is called |
| A. | oxidation |
| B. | Imhoff tank |
| C. | lagoon |
| D. | skimming tank |
| Answer» B. Imhoff tank | |
| 4950. |
Which is the most practical and economical method for removal of suspended solid matter from polluted water ? |
| A. | Sedimentation |
| B. | Skimming off |
| C. | Chlorination |
| D. | Biological oxidation |
| Answer» B. Skimming off | |