Multiple Choice Questions and Answers on Chemical Engineering Stoichiometry

01. In the reaction, Ca + 2H2O = Ca(OH)2 + H2; what volume (c.c.) of hydrogen at STP would be liberated, when 8 gm of calcium reacts with excess water ? (Atomic weight of calcium = 40)

(A) 4480
(B) 2240
(C) 1120
(D) 0.4

Answer: Option A

02. A vapor whose partial pressure is less than its equilibrium vapor pressure is called a __________ vapor.

(A) Saturated
(B) Supersaturated
(C) Superheated
(D) None of these

Answer: Option C

03. Dissolving a solute in a solvent does not change its

(A) Specific heat
(B) Vapour pressure
(C) Viscosity
(D) None of these

Answer: Option D

04. Applicability of Clausius-Clapeyron Equation is subject to the condition that the

(A) Vapor follows ideal gas law
(B) Volume in the liquid state is negligible
(C) Both (A) & (B)
(D) Neither (A) nor (B)

Answer: Option C

05. ‘Cox’ chart which is useful in the design of a distillation column (particularly suitable for petroleum hydrocarbons) is a plot of the

(A) Temperature vs. log (vapor pressure)
(B) Vapor pressure vs. log (temperature)
(C) Log (temperature) vs. log (vapor pressure)
(D) Vapor pressure vs. temperature

Answer: Option A

06. The reaction A + B → C has been conducted in a reactor as shown below. The number of boundaries around which material balance can be written, are

(A) 1
(B) 6
(C) 3
(D) 4

Answer: Option D

07. Methane is mixed with stoichiometric proportion of oxygen and completely combusted. The number of additional specifications required to determine the product flow rate and composition is

(A) 0
(B) 1
(C) 2
(D) 3

Answer: Option A

08. The number of water molecules present in a drop of water weighing 0.018 gm is 6.023 × __________.

(A) 1026
(B) 1023
(C) 1020
(D) 1019

Answer: Option C

09. Concentration of a solution expressed in terms of __________ is independent of temperature.

(A) Molarity
(B) Normality
(C) Molality
(D) None of these

Answer: Option C

10. The amount of Zn (atomic weight = 65) required to form 224 c.c. of H2 at N.T.P. on treatment with dilute H2SO4will be __________ gm.

(A) 0.065
(B) 0.65
(C) 6.5
(D) 65

Answer: Option B

11. Pick out the correct conversion.

(A) 1 BTU =453.6 calories
(B) 1 BTU = 252 calories
(C) 1 calorie = 252 BTU
(D) 1 calorie = 453.6 BTU

Answer: Option B

12. A vapor that exists above its critical temperature is termed as a __________ vapor.

(A) Saturated
(B) Unsaturated
(C) Gaseous
(D) Sub-cooled

Answer: Option C

13. Othmer chart is useful in estimating the heat of

(A) Mixing
(B) Wetting
(C) Adsorption
(D) None of these

Answer: Option C

14. Pick out the wrong unit conversion of temperature.

(A) °R = 273 + °F
(B) Temperature difference of 1°K = 1°C = 9/5°F
(C) °C = (F- 32) × 0.555
(D) °F = (°C + 17.778) × 1.8

Answer: Option A

15. Pick out the wrong unit conversion of heat transfer rate.

(A) 1 kcal/hr= 1.163 Watt
(B) 1 Watt = 1.163 kcal/hr
(C) 1 BTU/ft2.hr = 2.712 kcal/m2.hr
(D) 1 kcal/m2.hr = 0.3687 BTU/ft2.hr = 1.163 Watt/m2

Answer: Option B

16. Viscosity of 1 centipoise is equal to 1 Centistoke in case of

(A) Water
(B) Mercury
(C) Carbon tetrachloride
(D) None of these

Answer: Option A

17. °API gravity of water at N.T.P. is about

(A) 0
(B) 1
(C) 10
(D) 100

Answer: Option C

18. Colligative properties of a dilute solution are those which depend entirely upon the

(A) Constitution of the solute
(B) Chemical composition of the solute
(C) Number of solute molecules contained in a given volume of the solvent
(D) None of these

Answer: Option A

19. Which of the following is insensitive to changes in pressure?

(A) Heat of vaporisation
(B) Melting point
(C) Heat of fusion
(D) Both (B) and (C)

Answer: Option D

20. The heats of vaporisation of CS2, C2H5OH &H2O are 26.8, 38.6 & 40.6 KJ/kg.mole respectively. The order of decreasing inter-molecular forces in these liquids is

(A) H2O > C2H5OH > CS2
(B) CS2 > C2H5OH > H2O
(C) H2O > CS2 > C2H5OH
(D) CS2 > H2O > C2H5OH

Answer: Option A

21. 1 BTU/lb.←°F is equivalent to __________ kcal/kg.°C.

(A) 1
(B) 2.42
(C) 1.987
(D) 4.97

Answer: Option A

22. The gravimetric (i.e., by weight) composition of a vapor saturated gas is independent of the

(A) Nature of both the gas & the liquid
(B) Temperature
(C) Total pressure
(D) None of these

Answer: Option D

23. A gas occupies a volume of 283 c.c at 10°C. If it is heated to 20°C at constant pressure, the new volume of the gas will be __________ c.c.

(A) 283
(B) 566
(C) 293
(D) 141.5

Answer: Option C

24. Heat of __________ of a fuel is called its calorific value.

(A) Formation
(B) Combustion
(C) Reaction
(D) Vaporisation

Answer: Option B

25. Dry air is a mixture of

(A) Vapors
(B) Gases
(C) Both (A) & (B)
(D) Neither (A) nor (B)

Answer: Option B