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.
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- A. Equilibrium constant
- B. Rate constant
- C. Conversion
- D. None of these
Explanation: The limiting reactant is consumed first, so it fixes the maximum extent of reaction and therefore the achievable conversion.
Correct answer: Conversion- A. 1 mm wc
- B. 1 Pascal
- C. 1 atm
- D. 1 mm Hg
Explanation: A torr is defined as approximately the pressure exerted by a 1 mm column of mercury, so 1 torr equals 1 mm Hg.
Correct answer: 1 mm Hg- A. 0.2500
- B. 0.2528
- C. 0.5000
- D. 0.5055
Explanation: One litre of solution weighs 1011 g, so it contains 0.0245 × 1011 = 24.77 g of H₂SO₄.
Correct answer: 0.5055- A. Increased yield
- B. Enrichment of product
- C. All A., B. & C.
- D. Heat conservation
Explanation: Recycle returns unreacted material or useful energy to the process, which can improve overall yield, enrich a product stream, and reduce…
Correct answer: All A., B. & C.- A. Dalton's
- B. Avogadro's
- C. Gay-Lussac's
- D. Amagat's
Explanation: Amagat’s law states that the total volume of a gas mixture equals the sum of the component volumes, each measured at the mixture…
Correct answer: Amagat's- A. Twaddell scale
- B. Baume scale
- C. API scale
- D. None of these
Explanation: The Twaddell scale is designed for liquids with specific gravity greater than water.
Correct answer: Twaddell scale- A. 28 litres
- B. 35 ft3
- C. 4.5 litres
- D. 4.5 ft3
Explanation: Since 1 metre equals 3.2808 feet, 1 m³ equals 3.2808³, or about 35.3 ft³. Thus 35 ft³ is the closest option.
Correct answer: 35 ft3- A. Nuclear
- B. Liquid
- C. Gaseous
- D. Solid
Explanation: Solid fuels generally need the greatest excess air because their fuel-air mixing is less uniform and combustion is slower than with liquid…
Correct answer: Solid- A. log (1/H+)
- B. - log (1/H+)
- C. 1/log H+
- D. None of these
Explanation: By definition, pH = -log[H+], which is equivalently written as log(1/[H+]).
Correct answer: log (1/H+)- A. 10-3
- B. 10-11
- C. 10-10
- D. 10-13
Explanation: At 25°C, pH + pOH = 14, so pOH = 14 - 3 = 11. Hence [OH−] = 10^-11 mol/L.
Correct answer: 10-11- A. 5
- B. 7
- C. < 7
- D. > 7
Explanation: Sulfuric acid produces hydrogen ions in water, making the solution acidic regardless of its stated concentration.
Correct answer: < 7- A. 580
- B. 640
- C. Data insufficient; can't be computed
- D. 1160
Explanation: At STP, 448 litres corresponds to 448/22.4 = 20 moles of butane. Its mass is 20 multiplied by its molar mass of 58 g/mol, giving 1160 g.
Correct answer: 1160- A. P ∝ 1/V, when temperature is constant
- B. P ∝ 1/V, when temperature & mass of the gas remain constant
- C. P ∝ V, at constant temperature & mass of the gas
- D. P/V = constant, for any gas
Explanation: For a fixed mass of gas at constant temperature, Boyle's law gives PV = constant, hence P is inversely proportional to V.
Correct answer: P ∝ 1/V, when temperature & mass of the gas remain constant- A. Specific volume
- B. Specific gravity
- C. Critical properties
- D. Thermal conductivity
Explanation: Group contribution methods estimate properties such as critical temperature, critical pressure and critical volume by summing…
Correct answer: Critical properties- A. Equilibrium
- B. Adiabatic
- C. Steady
- D. Unsteady
Explanation: The gas inventory in the receiving bottles changes during filling, so the process is unsteady.
Correct answer: Unsteady- A. 270
- B. 327
- C. 300
- D. 540
Explanation: At constant pressure, Charles's law gives V/T = constant on the absolute-temperature scale.
Correct answer: 327- A. Decrease on addition of Cl2
- B. None of these
- C. Decrease on increasing the pressure of the system
- D. Increase on addition of an inert gas at constant pressure
Explanation: Adding Cl2 shifts the equilibrium backwards, increasing pressure favours the side with fewer moles, and adding inert gas at constant…
Correct answer: None of these- A. Increase the partial pressure of I2
- B. Decrease the partial pressure of HI
- C. Diminish the degree of dissociation of HI
- D. None of these
Explanation: Adding H2, a product, shifts 2HI ⇌ H2 + I2 to the left by Le Chatelier’s principle.
Correct answer: Diminish the degree of dissociation of HI- A. Soluble and toxic organics
- B. Suspended solids
- C. Heavy metals and cyanides
- D. All A., B. & C.
Explanation: Toxic soluble organics, suspended solids, and heavy metals or cyanides can each harm aquatic organisms through toxicity, oxygen depletion…
Correct answer: All A., B. & C.- A. 0.1
- B. 1
- C. 5
- D. 25
Explanation: A commonly cited tolerable occupational concentration for nitrogen oxides is about 5 ppm.
Correct answer: 5