MCQOPTIONS
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MCQOPTIONS
This section includes 409 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
The heat of reaction__________________? |
| A. | Depends on the pressure only |
| B. | Depends on the mechanism of reaction only |
| C. | Depends on both pressure and mechanism of reaction |
| D. | Is independent of the mechanism of reaction |
| Answer» E. | |
| 102. |
The half life period ‘t’ of a zero order reaction as shown in the bellow figure, is equal to_________________? |
| A. | CA0/2K |
| B. | CA0/K |
| C. | 0.693/K |
| D. | 1/K |
| Answer» B. CA0/K | |
| 103. |
The half life period of a first order reaction is given by (where, K = rate constant) ? |
| A. | 1.5 K |
| B. | 2.5 K |
| C. | 0.693/K |
| D. | 6.93 K |
| Answer» D. 6.93 K | |
| 104. |
The gas phase reaction 2A ⇌ B is carried out in an isothermal plug flow reactor. The feed consists of 80 mole % A and 20 mole % inerts. If the conversion of A at the reactor exit is 50%, then CA/CA0 at the outlet of the reactor is _______________________? |
| A. | 2/3 |
| B. | 5/8 |
| C. | 1/3 |
| D. | 3/8 |
| Answer» C. 1/3 | |
| 105. |
The fractional volume change of the system for the isothermal gas phase reaction, A → 3B, between no conversion and complete conversion is___________________? |
| A. | 0.5 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 106. |
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 | |
| 107. |
The following gas phase reaction is taking place in a plug flow reactor. A stoichiometric mixture of A and B at 300 K is fed to the reactor. At 1 m along the length of the reactor, the temperature is 360 K. The pressure drop is negligible and an ideal gas behaviour can be assumed. Identify the correct expression relating the concentration of A at the inlet (CA0), concentration of A at 1m (CA) and the corresponding conversion of A (X) ? |
| A. | CA = 1.2 CA0 (1 – X)/(1 – 0.33X) |
| B. | CA = 1.2 CA0 (1 – X)/(1 – 0.5X) |
| C. | CA = 0.83 CA0 (1 – X)/(1 – 0.33X) |
| D. | CA = 0.83 CA0 (1 – X)/(1 – 0.5X) |
| Answer» D. CA = 0.83 CA0 (1 – X)/(1 – 0.5X) | |
| 108. |
The following half life data are available for the irreversible liquid phase reaction A → products. The overall order of reaction is __________________? |
| A. | 0.5 |
| B. | 1 |
| C. | 1.5 |
| D. | 2 |
| Answer» D. 2 | |
| 109. |
The first order gas phase reaction as shown in the bellow figure is conducted isothermally in batch mode. The rate of change of conversion with time is given by________________? |
| A. | dXA/dt = k1 (1 – XA)2 (1 + 2XA) |
| B. | dXA/dt = k1 (1 – XA) (1 + 0.5XA) |
| C. | dXA/dt = k1 (1 – XA) |
| D. | dXA/dt = k1 (1 – XA)/(1 + XA) |
| Answer» D. dXA/dt = k1 (1 – XA)/(1 + XA) | |
| 110. |
The first order series reaction as shown in the bellow figure 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 | |
| 111. |
The extent of a reaction is ___________________? |
| A. | Different for reactants and products |
| B. | Dimensionless |
| C. | Depends on the stoichiometric co-efficient |
| D. | All of the above |
| Answer» E. | |
| 112. |
The experimentally determined overall order of the reaction, A + B → C + D, is two. Then the__________________? |
| A. | Reaction is elementary with a molecularity of 2 |
| B. | Molecularity of the reaction is 2, but the reaction may not be elementary |
| C. | Reaction may be elementary with molecularity of 2 |
| D. | Reaction is elementary but the molecularity may not be 2 |
| Answer» B. Molecularity of the reaction is 2, but the reaction may not be elementary | |
| 113. |
The exit age distribution curve E(t) for an ideal CSTR with the average residence time, η, is given by__________________? |
| A. | e-t/η |
| B. | e-t/η/η |
| C. | 1 – e-t/η |
| D. | 1 – (e-t/η/η) |
| Answer» C. 1 – e-t/η | |
| 114. |
The exit age distribution of a fluid leaving a vessel (denoted by E) is used to study the extent of non-ideal flow in the vessel. The value of ∫∞ 0 E.dt is____________________? |
| A. | 0 |
| B. | 1 |
| C. | ∞ |
| D. | √2π |
| Answer» C. ∞ | |
| 115. |
The exit age distribution of fluid leaving a vessel is used to know the__________________? |
| A. | Activation energies of a reaction |
| B. | Reaction mechanism |
| C. | Extent of non-ideal flow in the vessel |
| D. | None of these |
| Answer» D. None of these | |
| 116. |
The excess energy of the reactants required to dissociate into products is known as the ________________ energy? |
| A. | Thermal |
| B. | Activation |
| C. | Threshold |
| D. | Binding |
| Answer» C. Threshold | |
| 117. |
The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the _______________ energy? |
| A. | Activation |
| B. | Potential |
| C. | Binding |
| D. | Threshold |
| Answer» B. Potential | |
| 118. |
The equilibrium constant ‘K’ of a chemical reaction depends on_________________? |
| A. | Temperature only |
| B. | Pressure only |
| C. | Temperature and pressure |
| D. | Ratio of reactants |
| Answer» B. Pressure only | |
| 119. |
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 |
| Answer» D. Unpredictable from the data | |
| 120. |
The equilibrium constant for the reversible reaction as shown in the bellow figure, is affected by the__________________? |
| A. | Temperature of the system |
| B. | Presence or absence of inerts |
| C. | Pressure of the system |
| D. | Kinetics of the reaction |
| Answer» D. Kinetics of the reaction | |
| 121. |
The enzyme which can catalyse the conversion of glucose to ethyl alcohol is ___________________? |
| A. | Invertase |
| B. | Maltase |
| C. | Diastase |
| D. | Zymase |
| Answer» E. | |
| 122. |
The energy of activation of a chemical reaction ? |
| A. | Is same as heat of reaction at constant pressure |
| B. | Is the minimum energy which the molecules must have before the reaction can take place |
| C. | Varies as fifth power of the temperature |
| D. | Both B. and C. |
| Answer» C. Varies as fifth power of the temperature | |
| 123. |
The energy balance equation over a tubular reactor under transient conditions is________________? |
| A. | An ordinary non-linear differential equation |
| B. | An algebraic differential equation |
| C. | A linear partial differential equation |
| D. | A non-linear partial differential equation |
| Answer» D. A non-linear partial differential equation | |
| 124. |
The effectiveness factor for large value of Thiele modulus [L√(K/D1)] of a solid catalysed first order reaction is equal to (where, L = length of the reactor, cm, D1 = diffusion co-efficient, cm2/second) ? |
| A. | L √(K/D1) |
| B. | 1/[L√(K/D1)] |
| C. | 1 |
| D. | ∞ |
| Answer» C. 1 | |
| 125. |
The effect of increasing pressure on the gaseous equilibrium of the reaction 2X + 3Y ⇌ 3X + 2Y indicates that____________________? |
| A. | Pressure has no effect |
| B. | Backward reaction is favoured |
| C. | Forward reaction is favoured |
| D. | None of these |
| Answer» B. Backward reaction is favoured | |
| 126. |
The eddy diffusivity for a liquid in plug flow must be_________________? |
| A. | 1 |
| B. | 0 |
| C. | ∞ |
| D. | Between 0 and 1 |
| Answer» C. ∞ | |
| 127. |
The ‘E’ curve for a non-ideal reactor defines the fraction of fluid having age between t and t + dt _____________________? |
| A. | At the inlet |
| B. | At the outlet |
| C. | In the reactor |
| D. | Averaged over the inlet and outlet |
| Answer» C. In the reactor | |
| 128. |
The dispersion number of perfect mixed flow is__________________? |
| A. | 0 |
| B. | > 150 |
| C. | ∞ |
| D. | < 2100 |
| Answer» D. < 2100 | |
| 129. |
The dimensions of rate constant for reaction 3A → B are (l/gm mole)/min. Therefore the reaction order is______________________? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 130. |
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 | |
| 131. |
The conversion in a mixed reactor/accomplishing a reaction A → 3R is 50% when gaseous reactant ‘A’ is introduced at the rate of 1 litre/second and the leaving flow rate is 2 litres/second. The holding time for this operation is _______________ second? |
| A. | 0.5 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» B. 1 | |
| 132. |
The conversion for a first order liquid phase reaction. A → B in a CSTR is 50%. If another CSTR of the same volume is connected in series, then the % conversion at the exit of the second reactor will be_____________________? |
| A. | 60 |
| B. | 75 |
| C. | 90 |
| D. | 100 |
| Answer» C. 90 | |
| 133. |
The conversion of a reactant, undergoing a first order reaction, at a time equal to three times the half life of the reaction is ? |
| A. | 0.875 |
| B. | 0.5 |
| C. | 0.425 |
| D. | Data insufficient to calculate |
| Answer» B. 0.5 | |
| 134. |
The conversion for a second order, irreversible reaction (constant volume) as shown in the bellow figure, in batch mode is given by______________? |
| A. | 1/(1 + k2 . CA0 . t) |
| B. | (k2 . CA0 . t)/ (1 + k2 . CA0 . t) |
| C. | (k2 . CA0 . t)2/ (1 + k2 . CA0 . t) |
| D. | (k2 . CA0 . t)/ (1 + k2 . CA0 . t)2 |
| Answer» C. (k2 . CA0 . t)2/ (1 + k2 . CA0 . t) | |
| 135. |
The concentration of A in a first order reaction, A → B, decreases_____________________? |
| A. | Linearly with time |
| B. | Exponentially with time |
| C. | Very abruptly towards the end of the reaction |
| D. | Logarithmically with time |
| Answer» C. Very abruptly towards the end of the reaction | |
| 136. |
The catalytic converter for conversion of SO2 to SO3 by contact process should have a feed with SO2 content between___________________? |
| A. | 2-5 % |
| B. | 7-10 % |
| C. | 12-15 % |
| D. | 20-25 % |
| Answer» C. 12-15 % | |
| 137. |
The catalytic activity of enzymes is due to their capacity to lower the ______________ energy? |
| A. | Activation |
| B. | Potential |
| C. | Kinetic |
| D. | None of these |
| Answer» B. Potential | |
| 138. |
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 |
| Answer» C. Only | |
| 139. |
The catalyst in a first order chemical reaction changes the_________________? |
| A. | Equilibrium constant |
| B. | Activation energy |
| C. | Heat of formation of the product |
| D. | Heat of reaction |
| Answer» C. Heat of formation of the product | |
| 140. |
Second order consecutive irreversible reaction as shown in the bellow figure, were carried out in a constant volume isothermal batch reactor with different initial feed compositions. Reactor temperature was same in all the cases. In experiments where the ratio of concentration of B to that of A in the initial feed was less than 0.5, the concentration of B increased first, reached a maximum and then declined with time. However, for all experiments where this concentration ratio was 0.5 or above, concentration of B decreased monotonically with time right from the beginning. What is the ratio of the two rate constants (k1/k2) ? |
| A. | 1/4 |
| B. | 1/2 |
| C. | 2 |
| D. | 4 |
| Answer» B. 1/2 | |
| 141. |
Reverse reaction in a chemical equilibrium is favoured by the________________? |
| A. | Removal of one of the products regularly |
| B. | Increase in the concentration of one of the products |
| C. | Increase in the concentration of one of the reactants |
| D. | None of these |
| Answer» C. Increase in the concentration of one of the reactants | |
| 142. |
________________ resistance is not involved in the combustion of a carbon particle? |
| A. | Gas film |
| B. | Ash |
| C. | Chemical reaction |
| D. | None of these |
| Answer» C. Chemical reaction | |
| 143. |
Recycling back of outlet stream to the reactor from an ideal CSTR carrying out a first order liquid phase reaction will result in ______________ in conversion? |
| A. | Decrease |
| B. | Increase |
| C. | No change |
| D. | Either A. or B., depends on the type of reaction |
| Answer» D. Either A. or B., depends on the type of reaction | |
| 144. |
Reactions with high activation energy are_____________________? |
| A. | Very temperature sensitive |
| B. | Temperature insensitive |
| C. | Always irreversible |
| D. | Always reversible |
| Answer» B. Temperature insensitive | |
| 145. |
Reaction rate equation for the bellow figure reaction, If S at is present in large excess, what is the order of this reaction ? |
| A. | Zero |
| B. | One |
| C. | Two |
| D. | Three |
| Answer» C. Two | |
| 146. |
Reaction rate of a first order reaction, which is half completed in 23 minutes will be _________________? |
| A. | 0.03 sec-1 |
| B. | 0.03 min-1 |
| C. | 0.03 hr-1 |
| D. | 0.05 min-1 |
| Answer» C. 0.03 hr-1 | |
| 147. |
Reaction of benzene with chlorine gas to produce tri-chlorobenzene exemplifies a/an ______________ reaction? |
| A. | Elementary |
| B. | Parallel |
| C. | Consecutive |
| D. | None of these |
| Answer» D. None of these | |
| 148. |
Rate of a gaseous phase reaction is given by the reaction shown in the bellow figure. The unit of rate constant is__________________? |
| A. | (atm)-1 |
| B. | (hr)-1 |
| C. | (atm)-1.(hr)-1 |
| D. | atm.(hr)-1 |
| Answer» D. atm.(hr)-1 | |
| 149. |
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. | |
| 150. |
Rate of an autocatalytic chemical reaction is a function of ___________________? |
| A. | Temperature only |
| B. | Pressure only |
| C. | Composition only |
| D. | All A., B. and C. |
| Answer» E. | |