MCQOPTIONS
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MCQOPTIONS
This section includes 689 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
Air at a temperature of 20°C and 750 mm Hg pressure has a relative humidity of 80%. What is its percentage humidity ? Vapour pressure of water at 20°C is 17.5 mm Hg.$ |
| A. | 80.38 |
| B. | 80 |
| C. | 79.62 |
| D. | 78.51 |
| Answer» D. 78.51 | |
| 502. |
The vapor pressure of liquids (having similar chemical nature) at any specified temperature __________ with increasing molecular weight. |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | increases linearly |
| Answer» C. remains unchanged | |
| 503. |
Viscosity of 1 centipoise is equal to 1 centis-toke in case of |
| A. | water |
| B. | mercury |
| C. | carbon tetrachloride |
| D. | none of these |
| Answer» B. mercury | |
| 504. |
The depression in freezing point of a solution is |
| A. | inversely proportional to the mass of solvent. |
| B. | directly proportional to the mole of solute. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 505. |
In a mixture of benzene vapor and nitrogen gas at a total pressure of 900 mm Hg, if the absolute humidity of benzene is 0.2 kg benzene/kg nitrogen, the partial pressure of benzene in mm Hg is |
| A. | 180 |
| B. | 60.3 |
| C. | 720 |
| D. | 200 |
| Answer» C. 720 | |
| 506. |
During a phase change process like sublimation, vaporisation, melting etc., the specific __________ does not change. |
| A. | enthalpy |
| B. | Gibbs free energy |
| C. | internal energy |
| D. | entropy |
| Answer» C. internal energy | |
| 507. |
With rise in temperature, the heat capacity of a substance |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | either (a) or (b); depends on the substance |
| Answer» B. decreases | |
| 508. |
A solution with reasonably permanent pH is called a/an __________ solution. |
| A. | ideal |
| B. | non-ideal |
| C. | buffer |
| D. | colloidal |
| Answer» D. colloidal | |
| 509. |
At standard conditions, N2 + 2O2 2NO2; ΔG° = 100 kJ/moleNO + O2 2NO2; ΔG° = -35 kJ/moleThe standard free energy of formation of NO in kJ/mole is$ |
| A. | 15 |
| B. | 30 |
| C. | 85 |
| D. | 170 |
| Answer» D. 170 | |
| 510. |
A chemical process is said to occur under unsteady state, if the |
| A. | inventory changes do not take place. |
| B. | ratio of streams entering/leaving are independent of time. |
| C. | flow rates & composition both are time dependent. |
| D. | none of these. |
| Answer» D. none of these. | |
| 511. |
For water evaporating into usaturated air under adiabatic conditions and at constant pressure, the __________ remains constant throughout the period of vaporisation. |
| A. | dry bulb temperature |
| B. | wet bulb temperature |
| C. | humidity |
| D. | relative saturation |
| Answer» C. humidity | |
| 512. |
N.T.P. corresponds to |
| A. | 1 atm.absolute pressure& 0°C. |
| B. | 760 mm Hg gauge pressure & 0°C. |
| C. | 760 torr & 15°C. |
| D. | 101.325 KPa gauge pressure & 0°C. |
| Answer» B. 760 mm Hg gauge pressure & 0¬∞C. | |
| 513. |
A reduction process is accompanied with increase in the |
| A. | number of electrons |
| B. | oxidation number |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» B. oxidation number | |
| 514. |
__________ fuels require the maximum percentage of 'excess air' for complete combustion. |
| A. | Solid |
| B. | Liquid |
| C. | Gaseous |
| D. | Nuclear |
| Answer» B. Liquid | |
| 515. |
One kg of saturated steam at 100°C and 1.01325 bar is contained in a rigid walled vessel. It lias a volume of 1.673 m3. It cools to 98°C ; the saturation pressure is 0.943 bar ; one kg of water vapour under these conditions has a volume of 1.789 m3. The latent heat of condensation (kJ/kg-1 ) under these conditions is$ |
| A. | 40732 |
| B. | 2676 |
| C. | 2263 |
| D. | 540 |
| Answer» D. 540 | |
| 516. |
The forces causing the vaporisation of liquid are derived from the Kinetic energy of translation of its molecules. The heat of vaporisation |
| A. | increases with pressure rise. |
| B. | decreases with increasing pressure. |
| C. | becomes zero at the critical point. |
| D. | both (b) & (c). |
| Answer» E. | |
| 517. |
The vapor pressure of the solvent decreased by 10 mm Hg, when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction of the solvent, if the decrease in vapor pressure of the solvent is required to be 20 mm Hg. ? |
| A. | 0.2 |
| B. | 0.1 |
| C. | 0.4 |
| D. | 0.6 |
| Answer» E. | |
| 518. |
Pick out the wrong conversion formula for the conversion of weight units : |
| A. | 1 tonne = 1000 kg = 22.046 lbs |
| B. | 1 U.S. ton = 907 kg = 0.907 tonne = 0.893 ton |
| C. | 1 ton = 2240 lbs = 1016 kg = 1.016 tonnes = 1.12 U.S. tons |
| D. | none of these |
| Answer» E. | |
| 519. |
A butane isomerisation process produces 70 kmole/hr of pure isobutane. A purge stream removed continuously, contains 85% n-butane and 15% impurity (mole%). The feed stream is n-butane containing 1% impurity (mole%). The flow rate of the purge stream will be |
| A. | 3 kmole/hr |
| B. | 4 kmole/hr |
| C. | 5 kmole/hr |
| D. | 6 kmole/hr |
| Answer» D. 6 kmole/hr | |
| 520. |
What fraction of the total pressure is exerted by oxygen, if equal weights of oxygen and methane are mixed in an empty vessel at 25°C ?$ |
| A. | 43526 |
| B. | 43525 |
| C. | 43497 |
| D. | l/3 x |
| Answer» C. 43497 | |
| 521. |
The pH value of a solution is 5.9. If the hydrogen ion concentration is decreased hundred times, the solution will be |
| A. | basic |
| B. | more acidic |
| C. | neutral |
| D. | of the same acidity |
| Answer» B. more acidic | |
| 522. |
Which of the following is not a unit of kinematic viscosity ? |
| A. | Poise |
| B. | Stoke |
| C. | cm2/second |
| D. | None of these |
| Answer» B. Stoke | |
| 523. |
The value of (Cp - Cv)for a real gas obeying Vander Wall's equation is |
| A. | R |
| B. | > R |
| C. | < R |
| D. | 0.5 R |
| Answer» C. < R | |
| 524. |
Assume that benzene is insoluble in water. The normal boiling points of benzene and water are 80.1 and 100°C respectively. At a pressure of 1 atm, the boiling point of a mixture of benzene and water is$ |
| A. | 80.1°C. |
| B. | less than 80.1°C. |
| C. | 100°C. |
| D. | greater than 80.1°C but less than 100°C. |
| Answer» E. | |
| 525. |
Pick out the wrong unit conversion of thermal conductivity. |
| A. | 1 BTU/ft2.hr.°F/ft = 1.488 kcal/m2. hr.°C/m |
| B. | 1 BTU/ft2.hr.°F/inch = 1.488 kcal/m2. hr.°C/m |
| C. | 1 kcal/m.hr.°C = 0.672 BTU/ft.hr.°F = 1.163 W/m. °K |
| D. | 1 W/cm.°C = 85.985 kcal/m.hr.°C = 57.779 BTU/ft.hr.°F |
| Answer» C. 1 kcal/m.hr.¬∞C = 0.672 BTU/ft.hr.¬∞F = 1.163 W/m. ¬∞K | |
| 526. |
Heat of reaction is a function of the |
| A. | pressure |
| B. | temperature |
| C. | both(a)&(b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 527. |
Degrees of freedom will be equal to the number of components for a system comprising of |
| A. | only soluble liquid components. |
| B. | partially miscible two liquid components system having two phases. |
| C. | two liquid components and one solute (soluble in both the liquids). |
| D. | none of these. |
| Answer» B. partially miscible two liquid components system having two phases. | |
| 528. |
1 gm mole of methane (CH4) contains |
| A. | 6.02 x 1023 atoms of hydrogen. |
| B. | 4 gm atoms of hydrogen. |
| C. | 3.01 x 1023 molecules of methane. |
| D. | 3 gms of carbon. |
| Answer» C. 3.01 x 1023 molecules of methane. | |
| 529. |
1 Pascal (unit of pressure) is equal to __________ N/m2. |
| A. | 10 |
| B. | 1 |
| C. | 0.1 |
| D. | 1000 |
| Answer» C. 0.1 | |
| 530. |
1 kg/cm2 is equal to |
| A. | 760 torr |
| B. | 1KPa |
| C. | 10 metres of water column |
| D. | 1 metre of water column |
| Answer» D. 1 metre of water column | |
| 531. |
A vapor whose partial pressure is less than its equilibrium vapor pressure is called the __________ vapor. |
| A. | saturated |
| B. | superheated |
| C. | unsaturated |
| D. | dry gaseous |
| Answer» C. unsaturated | |
| 532. |
The maximum adiabatic flame temperature of fuels in air is __________ the maximum flame temperature in pure oxygen. |
| A. | lower than |
| B. | higher than |
| C. | same as |
| D. | not related to |
| Answer» B. higher than | |
| 533. |
The atomic heat capacities of all solid elements __________ with decrease in temperature. |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | approach zero at 0°C |
| Answer» C. remains unchanged | |
| 534. |
The vapor pressure of liquids of similar chemical nature at any particular temperature __________ with increase in the molecular weight. |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | either (a) or (b); depends on the liquid |
| Answer» C. remains unchanged | |
| 535. |
Which of the following is not a unit of length ? |
| A. | Parsec |
| B. | Angstrom |
| C. | Barn |
| D. | Fermi |
| Answer» D. Fermi | |
| 536. |
Viscosity of atmospheric air may be about __________ centipoise. |
| A. | 0.015 |
| B. | 1.5 |
| C. | 15 |
| D. | 150 |
| Answer» B. 1.5 | |
| 537. |
The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. If, at a total pressure of one standard atm. exerted by the vapours of water and toluene, the mole fraction of water Xw in the vapour phase satisfies$ |
| A. | 0 < Xw < 0.5 |
| B. | Xw = 0.5 |
| C. | 0.5 < Xw < 1.0 |
| D. | Xw = 1.0 |
| Answer» D. Xw = 1.0 | |
| 538. |
If a solution of eutectic composition is cooled, __________ reaching the eutectic temperature. |
| A. | the solvent begins to freeze out even before |
| B. | it will undergo no change until |
| C. | it will not solidify even on |
| D. | none of these |
| Answer» C. it will not solidify even on | |
| 539. |
The pressure under which liquid and vapor can co-exit at equilibrium is called the __________ vapor pressure. |
| A. | limiting |
| B. | real |
| C. | saturated |
| D. | normal |
| Answer» D. normal | |
| 540. |
Dissolving a solute in a solvent does not change its |
| A. | specific heat |
| B. | vapour pressure |
| C. | viscosity |
| D. | none of these |
| Answer» E. | |
| 541. |
A perfectly insulated container of volume V is divided into two equal halves by a partition. One side is under vacuum, while the other side has one mole of an ideal gas (with constant heat capacity) at 298 K. If the partition is broken, the final temperature of the gas in the container |
| A. | will be greater than 298 K. |
| B. | will be 298 K. |
| C. | will be less than 298 K. |
| D. | can not be determined. |
| Answer» D. can not be determined. | |
| 542. |
The number of atoms of oxygen present in 11.2 litres of ozone (O3) at N.T.P. are |
| A. | 3.01 x 1022 |
| B. | 6.02 x 1023 |
| C. | 9.03 x 1024 |
| D. | 1.20 x 1024 |
| Answer» D. 1.20 x 1024 | |
| 543. |
If the pressure of a gas is reduced to half & its absolute temperature is doubled, then the volume of the gas will |
| A. | be reduced to l/4th. |
| B. | increase four times. |
| C. | increase two times. |
| D. | none of these. |
| Answer» C. increase two times. | |
| 544. |
Atmospheric pressure corresponds to a hydrostatic head of |
| A. | 13.6 cms of Hg |
| B. | 34 ft ofH2O |
| C. | 1 metre of H2O |
| D. | 13.6 metres of Hg |
| Answer» C. 1 metre of H2O | |
| 545. |
1 torr is equivalent to |
| A. | 1 mm Hg |
| B. | 1 Pascal |
| C. | 1 ata |
| D. | 1 mm wc |
| Answer» B. 1 Pascal | |
| 546. |
Othmer chart is useful in estimating the heat of |
| A. | mixing |
| B. | wetting |
| C. | adsorption |
| D. | none of these |
| Answer» D. none of these | |
| 547. |
In case of a solution (not of a solid in a liquid), whose total volume is less than the sum of the volumes of its components in their pure states, solubility is |
| A. | independent of temperature. |
| B. | increases with rise in pressure. |
| C. | increased with decrease in pressure. |
| D. | unchanged with pressure changes. |
| Answer» C. increased with decrease in pressure. | |
| 548. |
Heat of transition is the heat evolved or absorbed, when a substance is converted from |
| A. | vapor to liquid. |
| B. | vapor to solid. |
| C. | solid to liquid. |
| D. | one allotropic form to another allotropic form. |
| Answer» E. | |
| 549. |
The effect of pressure on the heat capacity of the gases __________ is negligible. |
| A. | at pressure below one atmosphere |
| B. | below the critical temperature |
| C. | both(a)&(b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 550. |
What is the simplest formula of a compound containing 50% of element A (atomic weight = 10) and 50% of element B (atomic weight = 20) ? |
| A. | AB3 |
| B. | A2B3 |
| C. | A2B |
| D. | AB2 |
| Answer» B. A2B3 | |