chemical engineering Mcqs
8401. The forces causing the vaporisation of liquid are derived from the Kinetic energy of translation of its molecules. The heat of vaporisation_________________?
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A. Increases with pressure rise

B. Decreases with increasing pressure

C. Becomes zero at the critical point

D. Both B. & C.
8402. For a real gas, the chemical potential is given by_____________________?
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A. None of these

B. R d ln f

C. RT d ln P

D. RT d ln f
8403. Boyles law for gases states that____________________?
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A. P ? 1/V, when temperature is constant

B. P ? V, at constant temperature & mass of the gas

C. P ? 1/V, when temperature & mass of the gas remain constant

D. P/V = constant, for any gas

8404. The internal energy of an ideal gas does not change in a reversible _____________ process?
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A. Isothermal

B. Isobaric

C. Adiabatic

D. Isometric

8405. The combustion equations of carbon and carbon monoxide are as follows: C + O2 = CO2, ?H = 394 kJ/kg .mole CO + O2 = CO2, ?H = 284.5 kJ/kg. mole. The heat of formation of CO is _____________ kJ/kg. mole?
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A. 180

B. 109.5

C. 100

D. -109.5
8406. Free energy___________________?
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A. Decreases in all spontaneous (or irreversible) processes

B. Change during a spontaneous process has a negative value

C. All A, B. and C

D. Remains unchanged in reversible processes carried at constant temperature and pressure

8407. With increase in temperature, the internal energy of a substance___________________?
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A. Increases

B. Decreases

C. Remains unchanged

D. May increase or decrease; depends on the substance

8408. Which of the following represents the Virial equation of state ?
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A. n1u2 + ?2?1 = 0

B. PV/RT = 1 + (B/V) + (C/V2) +

C. T = [RT/(V- b)] [a/?T. V(V + b)]

D. None of these

8409. A system in which there is exchange of energy but not of mass, is called a/an ____________ system?
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A. Isolated

B. Open

C. Insulated

D. Closed
8410. As the temperature is lowered towards the absolute zero, the value of ?(?F)/?T, then approaches_______________________?
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A. Infinity

B. Unity

C. That of the heat of reaction

D. Zero
8411. The amount of heat required to decompose a compound into its elements is _____________ the heat of formation of that compound from its elements?
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A. Less than

B. More than

C. Not related to

D. Same as
8412. The chemical potential for a pure substance is ____________ its partial molal free energy?
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A. More than

B. Less than

C. Not related to

D. Equal to
8413. The enthalpy change when ammonia gas is dissolved in water is called the heat of___________________?
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A. Combustion

B. Dilution

C. Formation

D. Solution
8414. Heat is added at constant pressure in an ideal _____________ cycle?
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A. Stirling

B. Brayton

C. Rankine

D. Both B. and C
8415. The difference between isothermal compressibility and adiabatic compressibility for an ideal gas is____________________?
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A. +ve

B. ?

C. 0

D. #NAME?

8416. Free energy change at equilibrium is____________________?
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A. Positive

B. Zero

C. Indeterminate

D. Negative

8417. For any system, what is the minimum number of degrees of freedom ?
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A. 2

B. 3

C. 1

D. 0
8418. In any spontaneous process, ?
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A. Only F decreases

B. Only A decreases

C. Both F and A decreases

D. Both F and A increase

8419. Equation which relates pressure, volume and temperature of a gas is called the__________________?
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A. Equation of state

B. Ideal gas equation

C. None of these

D. Gibbs Duhem equation

8420. Which of the following is followed by an ideal solution ?
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A. Raoults law

B. Amagats law

C. Boyles law

D. Troutons rule

8421. The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 T2)/T1. The co-efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2 is given by__________________?
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A. T2/(T1-T2)

B. T1/T2

C. T2/R1

D. T1/(T1-T2)
8422. In case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when_______________?
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A. n = y = 1.4

B. n = 1

C. n = 1.66

D. n = 0

8423. 1 torr is equivalent to_________________?
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A. 1 mm wc

B. 1 Pascal

C. 1 atm

D. 1 mm Hg
8424. What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, TR (where, T1 and T2 are source & surrounding temperatures respectively.) ?
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A. TR/(T2 TR) (T1 T2)/T1

B. TR/(T2 TR) T1/(T1 T2)

C. None of these

D. TR/(T1 TR) (T1 T2)/T1

8425. Heat requirement for decomposition of a compound into its elements is _____________ that is evolved during the formation of that compound from its elements?
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A. Less than

B. Greater than

C. Different than

D. The same
8426. _______________ increases with increase in pressure?
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A. The melting point of wax

B. The boiling point of a liquid

C. Both A. and B

D. Neither A. nor B

8427. COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about____________________?
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A. 3.5

B. 4.5

C. 0.5

D. 8.5

8428. A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect ?
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A. Carnot refrigeration cycle

B. Vapor compression cycle using expansion valve

C. Air refrigeration cycle

D. Vapor compression cycle using expansion engine

8429. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is____________________?
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A. 320,000 kW

B. 160,000 kW

C. 200,000 kW

D. 100,000 kW

8430. In the reaction, H2 +I2 ? 2HI, addition of an inert gas will___________________?
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A. Increase the partial pressure of I2

B. Increase the total pressure and hence shift the equilibrium towards the right

C. Increase the partial pressure of H2

D. Not affect the equilibrium conditions
8431. A/an ____________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor?
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A. Isolated

B. Open

C. None of these

D. Closed

8432. Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor) ?
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A. Liquid sulphur dioxide

B. Methyl chloride

C. Freon

D. Ammonia

8433. The value of gas constant R is__________________?
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A. 1.987 cal/gm mole K

B. 1.987 BTU/lb. mole R

C. Both A. and B

D. Neither A. nor B

8434. The equation Tds = dE PdV applies to___________________?
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A. Single phase fluid of varying composition

B. Single phase fluid of constant composition

C. Open as well as closed systems

D. Both B. and C
8435. Which of the following is not correct for a reversible adiabatic process ?
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A. PV? = constant

B. None of these

C. TV?-1 = constant

D. p1-?.TY = constant

8436. If we increase the pressure on a substance (which is at its triple point), then the triple point __________________?
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A. Decreases

B. Remains unchanged

C. Increases

D. May increase or decrease; depends on the substance

8437. Heat of neutralisation of a strong acid and strong base is always a constant value, i.e., 57 KJ/Kg mole. This is because_________________?
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A. The salt formed does not hydrolyse

B. The strong base and strong acid reacts completely

C. The strong base and strong acid reacts in aqueous solution

D. Only OH- and H+ ions react in every case
8438. The unit of equilibrium constant of a chemical reaction is the same as that of__________________?
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A. Molar concentration

B. None of these

C. Internal energy

D. Temperature

8439. Boiling of liquid is accompanied with increase in the__________________?
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A. All (A), B. and (C)

B. Specific Gibbs free energy

C. Specific entropy

D. Vapor pressure
8440. ________________ decreases during adiabatic throttling of a perfect gas?
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A. Entropy

B. Pressure

C. Enthalpy

D. Temperature

8441. Extensive properties of a thermodynamic system depend upon the _____________ of the system?
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A. Temperature

B. Mass

C. Pressure

D. Specific volume

8442. The free energy change for a chemical reaction is given by (where, K = equilibrium constant)________________?
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A. -RT ln K

B. RT ln K

C. T ln K

D. -R ln K

8443. What is the number of degrees of freedom for liquid water in equilibrium with a mixture of nitrogen and water vapor ?
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A. 3

B. 1

C. 0

D. 2
8444. What is the number of degree of freedom for a system of two miscible non-reacting species in vapor-liquid equilibrium forming an azeotrope ?
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A. 2

B. 3

C. 1

D. 0

8445. A change in state involving a decrease in entropy can be spontaneous, only if ____________________?
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A. It takes place at constant volume

B. It is exothermic

C. It is isenthalpic

D. It takes place isothermally

8446. The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is________________?
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A. (?V/?S)P = (?T/?P)S

B. (?S/?V)T = (?P/?T)V

C. (?T/?V)S = (?P/?S)V

D. (?S/?P)T = (?V/?T)P

8447. No work is done by the system, when a reaction occurs at constant__________________?
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A. None of these

B. Pressure

C. Volume

D. Temperature

8448. pH value of H2SO4 (5% concentration) is__________________?
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A. 7

B. < 7

C. > 7

D. 5

8449. Grams of butane (C4H10) formed by the liquefaction of 448 litres of the gas (measured at (STP) would be__________________?
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A. Data insufficient; cant be computed

B. 640

C. 580

D. 1160
8450. The total change in the enthalpy of a system is independent of the _______________________?
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A. State of combination and aggregation in the beginning and at the end of the reaction

B. Pressure and temperature

C. None of these

D. Number of intermediate chemical reactions involved