Free Chemical Process Principles MCQs with Answers

2,710 Chemical Process Principles MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

Last updated

2,710 questions · page 75 of 136

  • A. Nature
  • B. Size
  • C. Absolute temperature
  • D. All A., B. & C.

Explanation: By kinetic theory, the average translational kinetic energy of gas molecules is proportional to absolute temperature, specifically 3RT/2…

Correct answer: Absolute temperature
  • A. 14
  • B. 2.5
  • C. 28
  • D. 1.25

Explanation: At NTP, nitrogen occupies about 22.4 L per mole, while one mole of N₂ weighs 28 g. Thus, 2 L weighs 28(2/22.4), approximately 2.5 g.

Correct answer: 2.5
  • A. 273°C
  • B. 273°K
  • C. 100°C
  • D. 200°C

Explanation: At constant pressure, Charles's law gives V/T = constant using absolute temperature.

Correct answer: 273°C
  • A. Joule
  • B. Watt
  • C. Both B. & C.
  • D. Joule/Second

Explanation: Power is the rate of doing work, so its SI unit is joule per second, which is named the watt.

Correct answer: Both B. & C.
  • A. Stoke
  • B. Poise
  • C. Both B. & C.
  • D. gm/cm sec

Explanation: Dynamic viscosity has the CGS unit poise, defined as gram per centimetre-second, or g/(cm·s).

Correct answer: Both B. & C.
  • A. Neither A. nor B.
  • B. Oxidation number
  • C. Both A. & B.
  • D. Number of electrons

Explanation: Reduction means gain of electrons, while oxidation number decreases during reduction.

Correct answer: Number of electrons
  • A. NH3
  • B. CO2
  • C. H2S
  • D. CH4

Explanation: Ammonia is highly soluble in water because it reacts with water to form ammonium and hydroxide ions.

Correct answer: NH3
  • A. T2
  • B. T
  • C. √T
  • D. 1/√T

Explanation: From kinetic theory, the characteristic molecular speed varies as the square root of absolute temperature, v ∝ √T.

Correct answer: √T
  • A. Weight % of the solute
  • B. Mole fraction of the solute
  • C. Molality
  • D. Molarity

Explanation: On heating, the solution volume generally expands while the amount of solute remains constant, so molarity decreases.

Correct answer: Molarity
  • A. C4H9OH
  • B. C3H21OH
  • C. (C2H4)2H2.OH
  • D. C2H33OH

Explanation: The carbon, hydrogen and oxygen amounts correspond to 48/12 = 4, 10/1 = 10 and 16/16 = 1 mole, giving C4H10O.

Correct answer: C4H9OH
  • A. °Be = 200(G-1)
  • B. °Be = (140/G) - 130
  • C. °Be = 145 - (145/G)
  • D. °Be = (400/G) - 400

Explanation: For liquids lighter than water, the specific gravity G is less than one, so the Baumé relation is °Be = 140/G − 130.

Correct answer: °Be = (140/G) - 130
  • A. 2.5
  • B. 42.5
  • C. 56
  • D. 2800

Explanation: At N.T.P., one gram-mole of an ideal gas occupies 22.4 L, so 56 L represents 2.5 moles.

Correct answer: 42.5
  • A. Litre
  • B. gm
  • C. gm.mole
  • D. kg

Explanation: Molality is based on the mass of solvent, not the solution volume: it is gram-moles of solute per kilogram of solvent.

Correct answer: kg
  • A. Buffer
  • B. Non-ideal
  • C. Ideal
  • D. Colloidal

Explanation: A buffer contains a weak acid and its conjugate base, or a weak base and its conjugate acid, so it resists pH changes when small amounts…

Correct answer: Buffer
  • A. Trouton's rule
  • B. Kopp's rule
  • C. Antoine equation
  • D. Kistyakowsky equation

Explanation: Kopp's rule estimates the molar heat capacity of a solid compound by adding the atomic heat capacities of its constituent elements.

Correct answer: Kopp's rule
  • A. N2O4
  • B. N2O3
  • C. N2O5
  • D. None of these

Explanation: The masses correspond to 28/14 = 2 gram-atoms of nitrogen and 80/16 = 5 gram-atoms of oxygen.

Correct answer: N2O5
  • A. Increases
  • B. Decreases
  • C. Remains unchanged
  • D. Either A. or B.; depends on the substance

Explanation: Over ordinary temperature ranges, the heat capacity of most substances increases because more molecular energy modes become accessible as…

Correct answer: Increases
  • A. - 136.5°K
  • B. -136.5°C
  • C. -273°C
  • D. 0°K

Explanation: At constant pressure, Charles's law gives V/T = constant using absolute temperature.

Correct answer: -136.5°C
  • A. 3
  • B. 100
  • C. 1000
  • D. None of these

Explanation: A pH decrease of one unit means a tenfold increase in hydrogen-ion concentration.

Correct answer: 1000
  • A. Formation
  • B. Vaporisation
  • C. Reaction
  • D. Combustion

Explanation: Calorific value is the heat released when a unit amount of fuel undergoes complete combustion.

Correct answer: Combustion