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.
| 301. |
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 | |
| 302. |
On application of pressure to the equilibrium system, ice ⇋ water; which of the following phenomenon will occur? |
| A. | Water will evaporate |
| B. | Equilibrium will not be attained |
| C. | More ice will be formed |
| D. | More water will be formed |
| Answer» E. | |
| 303. |
In the hydrodealkylation of toluene to benzene, the following reactions occur:C₇H₈ + H₂ → C₆H₆ + CH₄2C₆H₆ ⇋ C₁₂H₁₀ + H₂Toluene 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 |
| A. | 0.16 |
| B. | 0.144 |
| C. | 0.152 |
| D. | 0.136 |
| Answer» C. 0.152 | |
| 304. |
For every 10°C rise in temperature, the rate of chemical reaction doubles. When the temperature is increased from 30 to 70°C, the rate of reaction increases __________ times. |
| A. | 8 |
| B. | 12 |
| C. | 16 |
| D. | 32 |
| Answer» D. 32 | |
| 305. |
Calcination reaction of limestone (CaCO₃ → CaO + CO₂) goes to completion in the rotary kiln, because |
| A. | CaO is not dissociated |
| B. | CO₂ escapes continuously |
| C. | Of high calcination temperature |
| D. | CaO is more stable than CaCO₃ |
| Answer» C. Of high calcination temperature | |
| 306. |
With the same reaction time, initial concentration and feed rate, the reaction 2A → B is carried out separately in CSTR and P.F. reactor of equal volumes. The conversion will be |
| A. | Higher in P.F. reactor |
| B. | Higher in CSTR |
| C. | Same in both the reactors |
| D. | Data insufficient; can't be predicted |
| Answer» B. Higher in CSTR | |
| 307. |
For a tubular reactor with space time 'τ' and residence time 'θ', the following statement holds good. |
| A. | τ and θ are always equal |
| B. | τ = θ , when the fluid density changes in the reactor |
| C. | τ = θ , for an isothermic tubular reactor in which the density of the process fluid is constant |
| D. | τ = θ , for a non-isothermal reactor |
| Answer» D. τ = θ , for a non-isothermal reactor | |
| 308. |
From Arhenius law, a plot of loge K versus 1/T gives a straight line with a slope of (-E/R). The unit of E/R is |
| A. | K cal |
| B. | K cal/°K |
| C. | °K |
| D. | K cal. °K |
| Answer» D. K cal. °K | |
| 309. |
In the fluid catalytic cracker (FCC), the cracking reaction is __________ (i) and the regeneration is ____________ (ii) |
| A. | (i) exothermic (ii) endothermic |
| B. | (i) exothermic (ii) exothermic |
| C. | (i) endothermic (ii) enodthermic |
| D. | (i) endothermic (ii) exothermic |
| Answer» E. | |
| 310. |
For the chemical reaction P → Q, it is found that the rate of reaction doubles as the concentration of 'P' is doubled. If the reaction rate is proportional to Cpn, then what is the value of 'n' for this chemical reaction |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 0 |
| Answer» B. 2 | |
| 311. |
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 | |
| 312. |
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 | |
| 313. |
A CSTR is to be designed in which an exothermic liquid phase first order reaction of the type, A → R, is taking place. The reactor is to be provided with a jacket in which coolant is flowing. Following data is given: CA0= 5 kmole/m³ ; XA = 0.5; Feed temperature = reactor temperature = 40°C. Rate constant at 40°C = 1 min⁻¹ ; (ΔH) = - 40kJ/mole; ρ = 1000kg/m³ CP = 4 J/gm.°C ; q = 10⁻³ m³/min (ρ and CP are same for the reactant and product streams). The amount of heat to be removed is |
| A. | 2/3 kW |
| B. | 1kW |
| C. | 5/3 kW |
| D. | 4kW |
| Answer» D. 4kW | |
| 314. |
Which of the following is used for calcination of limestone and dolomite in industrial practice? |
| A. | Fluidised bed reactor |
| B. | Moving bed reactor |
| C. | Fixed bed reactor |
| D. | None of these |
| Answer» C. Fixed bed reactor | |
| 315. |
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 | |
| 316. |
A pollutant P degrades according to first order kinetics. An aqueous stream containing P at 2 kmole/m³ and volumetric flow rate 1m³ /h requires a mixed flow reactor of volume V to bring down the pollutant level to 0.5 kmole/m³ . The inlet concentration of the pollutant is now doubled and the volumetric flow rate is tripled. If the pollutant level is to be brought down to the same level of 0.5 kmole/m³ , the volume of the mixed flow reactor should be increased by a factor of |
| A. | 7 |
| B. | 6 |
| C. | 3 |
| D. | 7/3 |
| Answer» B. 6 | |
| 317. |
For the reversible reaction A ⇋ 2B, if the equilibrium constant K is 0.05 mole/litre; starting from initially 2 moles of A and zero moles of B, how many moles will be formed at equilibrium? |
| A. | 0.253 |
| B. | 0.338 |
| C. | 0.152 |
| D. | 0.637 |
| Answer» C. 0.152 | |
| 318. |
For the chemical reaction X → Y, it is observed that, on doubling the concentration of 'X', the reaction rate quadruples. If the reaction rate is proportional to Cxn, then what is the value of 'n' ? |
| A. | 4 |
| B. | 1/4 |
| C. | 16 |
| D. | 2 |
| Answer» B. 1/4 | |
| 319. |
In chamber process of sulphuric acid manufacture in industry, the gas phase oxidation of SO₂ to SO₃ is accomplished by a __________ reaction. |
| A. | Non-catalytic homogeneous |
| B. | Non-catalytic heterogeneous |
| C. | Catalytic homogenous |
| D. | Catalytic heterogeneous |
| Answer» D. Catalytic heterogeneous | |
| 320. |
If CA is the quantity of reactants initially present, the quantity left after 'n' half periods will be equal to |
| A. | (CA)n |
| B. | (1/2)n.CA |
| C. | (CA)1/n |
| D. | (CA)1/2n |
| Answer» C. (CA)1/n | |
| 321. |
The rate expression for a heterogenous catalytic reaction is given by, - rA = K.KA PA(1 + KA.PA + Kr.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR >> (1 + KA PA), the apparent activation energy EA is equal to (given E is the activation energy for the reaction and ΔHR and ΔHA are the activation energies of adsorption of R and A) |
| A. | E |
| B. | E + ΔHA |
| C. | E + ΔHA - ΔHR |
| D. | ΔHA + ΔHR |
| Answer» D. ΔHA + ΔHR | |
| 322. |
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% | |
| 323. |
For the liquid phase parallel reactions:R, rR = K?.CA2; E? = 80 KJ/moleS, rS = K?.CA ; E? = 120 KJ/moleThe desired product is R. A higher selectivity of R will be achieved, if the reaction is conducted at |
| A. | Low temperature in a CSTR |
| B. | High temperature in a CSTR |
| C. | Low temperature in a PFR |
| D. | High temperature in a PFR |
| Answer» E. | |
| 324. |
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/mole, Density of the reacting mixture = 1000kg/m³, Specific 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 | |
| 325. |
A pulse tracer is introduced in an ideal CSTR (with a mean residence time ι) at time, t = 0. The time taken for the exit concentration of the tracer to reach half of its initial value will be |
| A. | 2τ |
| B. | 0.5τ |
| C. | τ/0.693 |
| D. | 0.693τ |
| Answer» B. 0.5τ | |
| 326. |
An isothermal aqueous phase reversible reaction, P ⇋ R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m³ .h is given by, r = 0.5CP - 0.125CR. A stream containing only P enters the |
| A. | 0.80 |
| B. | 1.33 |
| C. | 1.60 |
| D. | 2.67 |
| Answer» D. 2.67 | |
| 327. |
The exit age distribution curve E(t) for an ideal CSTR with the average residence time, τ, is given by |
| A. | E-t/τ |
| B. | E-t/τ/T |
| C. | 1 - e-t/τ |
| D. | 1 - (e-t/τ/T) |
| Answer» C. 1 - e-t/τ | |
| 328. |
For the gaseous reaction 2A → B, where the feed consists of 50 mole % A and 50 mole % inerts, the expansion factor is |
| A. | 1 |
| B. | -0.5 |
| C. | -0.25 |
| D. | 0 |
| Answer» D. 0 | |
| 329. |
If in the gaseous phase reaction, N₂O₄ ⇋ 2NO₂, x is the part of N₂O₄ which dissociates, then the number of molecules at equilibrium will be |
| A. | (1 + x) |
| B. | (1 - x) |
| C. | (1 + x)² |
| D. | (1 - x)² |
| Answer» B. (1 - x) | |
| 330. |
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. | 100% |
| B. | 95% |
| C. | 75% |
| D. | 20% |
| Answer» C. 75% | |
| 331. |
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 | |
| 332. |
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 | |
| 333. |
For an isothermal second order aqueous phase reaction, A → B, the ratio of the time required for 90% conversion to the time required for 45% conversion is |
| A. | 2 |
| B. | 4 |
| C. | 11 |
| D. | 22 |
| Answer» D. 22 | |
| 334. |
Given,3H₂ + CO = CH₄ + H₂O, KP = 101.84 and,4H₂ + CO₂ = CH₄ + 2H₂O, KP = 101.17the KP for the reaction CO + H₂O = CO₂ + H₂ is |
| A. | 103.01 |
| B. | 10-0.67 |
| C. | 10-3.01 |
| D. | L00.67 |
| Answer» E. | |
| 335. |
Which of the following is not a dimension-less group used in catalysis ? (where, D = dispersion co-efficient, cm² /sec.D1 = diffusion co-efficient; cm²/sec L = length of the reactor, cm t = time, sec, v = volumetric flow rate, cm³/sec . V = volume, cm³.) |
| A. | Reactor dispersion number (D/vL) |
| B. | Reduced time (vt/V) |
| C. | Thiele modulus (L√(k/D1) |
| D. | None of these |
| Answer» E. | |
| 336. |
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 | |
| 337. |
If ΔG (free energy change) for a chemical reaction is very large and negative, then the reaction is |
| A. | Not feasible |
| B. | Just feasible |
| C. | Very much feasible |
| D. | Unpredictable as ΔG is no measure of feasibility of a reaction |
| Answer» D. Unpredictable as ΔG is no measure of feasibility of a reaction | |
| 338. |
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. | |
| 339. |
In the reversible reaction of the type, A + B ⇋ AB, in general |
| A. | Both forward and backward reactions will be exothermic |
| B. | Neither of the reactions will be en-dothermic |
| C. | The combination reaction will be exothermic, while the dissociation reaction will be endothermic |
| D. | The combination reaction will be endothermic, while the dissociation reaction will be exothermic |
| Answer» D. The combination reaction will be endothermic, while the dissociation reaction will be exothermic | |
| 340. |
The reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m³ is fed to the reactor at the rate of 0.01 m³ /s and at a temperature of 500 K. If the exit conversion is 20%, then the exit temperature (in k)is (Data: Heat of reaction at 298 K = - 50000 kJ/ kmole of A reacted Heat capacities CPA = CPB = 100kJ/kmole. K (may be assumed to be independent of temperature)) |
| A. | 400 |
| B. | 500 |
| C. | 600 |
| D. | 1000 |
| Answer» D. 1000 | |
| 341. |
The value of 'n' for a chemical reaction A → B, whose reaction rate is → CAn, will be __________ if the rate of the reaction increases by a factor of 8, when the concentration of is doubled. |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» E. | |
| 342. |
In the gaseous phase ammonia formation reaction (N₂ + 3H₂ ⇋ 2NH₃), the value of the equilibrium constant depends on the |
| A. | Total pressure of the system |
| B. | Volume of the reactor |
| C. | Temperature |
| D. | Initial concentration of N₂ and H₂ |
| Answer» D. Initial concentration of N₂ and H₂ | |
| 343. |
For reaction, P + 2 → 3R, molar rate of consumption of P is |
| A. | Double of that of Q |
| B. | Same as that of Q |
| C. | Half of that of Q |
| D. | 2/3rd of that of Q |
| Answer» D. 2/3rd of that of Q | |
| 344. |
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 | |
| 345. |
For the liquid phase zero order irreversible reaction A → B, the conversion of A in a CSTR is found to be 0.3 at a space velocity of 0.1min⁻¹ . What will be the conversion for a PFR with a space velocity of 0.2 min⁻¹? Assume that all the other operating conditions are the same for CSTR and PFR. |
| A. | 0.15 |
| B. | 0.30 |
| C. | 0.60 |
| D. | 0.90 |
| Answer» D. 0.90 | |
| 346. |
Half life period of a chemical reaction is proportional to CA0-1 , if the reaction is of __________ order. |
| A. | First |
| B. | Zero |
| C. | Second |
| D. | Third |
| Answer» D. Third | |
| 347. |
Fractional conversion __________ with increase in pressure for ammonia synthesis reaction i.e., N₂ + 3H₂ ⇋ 2NH₃. |
| A. | Increases |
| B. | Decreases |
| C. | Remains unchanged |
| D. | Unpredictable from the data |
| Answer» B. Decreases | |
| 348. |
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 | |
| 349. |
The value of steric factor 'P' in the equation k = PZeE/RT usually ranges from |
| A. | L.0 to 10⁻⁸ |
| B. | L.l.to 10² |
| C. | 0.1 to 0.9 |
| D. | None of these |
| Answer» B. L.l.to 10² | |
| 350. |
Pick the WRONG design guideline for a reactor in which the reactions, A → R (desired) and A → S (undesired) are to take place. The ratio of the reaction rates is rR/rS = (k₁/k₂).Csub>Aa-b |
| A. | Use high pressure and eliminate inerts, when a > b |
| B. | Avoid recycle, when a > b |
| C. | Use batch reactor or plug flow reactor, when a > b |
| D. | Use CSTR with a high conversion, when a > b |
| Answer» C. Use batch reactor or plug flow reactor, when a > b | |