All Free Chemical Engineering MCQs with Answers

Every Chemical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

6,983 questions · page 39 of 350

  • A. Asphyxiation
  • B. Shortness of breath
  • C. Both B. & C.
  • D. Tuberculosis

Explanation: Silica dust causes silicosis, whose important symptom is breathlessness, and silicosis also greatly increases susceptibility to pulmonary…

Correct answer: Both B. & C.
  • A. Troposphere
  • B. Stratosphere
  • C. Ionosphere
  • D. None of these

Explanation: The troposphere is the atmosphere’s lowest layer and contains most atmospheric mass and water vapour, so nearly all weather occurs in it.

Correct answer: Troposphere
  • A. Alkalis
  • B. Chlorine
  • C. Benzene hexachloride
  • D. Alkyl benzene sulphonate (ABS)

Explanation: Chlorine is widely used to disinfect water because it forms hypochlorous acid, a strong antimicrobial agent that destroys many water-borne…

Correct answer: Chlorine
  • A. Bone decay
  • B. Asphyxiation (suffocation)
  • C. Cancer
  • D. Anemia

Explanation: A carcinogen is an agent capable of initiating or promoting cancer, so carcinogenic air pollutants are linked directly with cancer.

Correct answer: Cancer
  • A. Dissolved gases
  • B. Color
  • C. Hardness
  • D. Turbidity

Explanation: Turbidity is the cloudiness of water caused by suspended particles that scatter or block light, so it measures resistance to light…

Correct answer: Turbidity
  • A. Grey
  • B. Dark brown
  • C. Red
  • D. Black

Explanation: Fresh domestic sewage is usually grey or light grey because it has not yet undergone significant anaerobic decomposition.

Correct answer: Grey
  • A. Positively charged
  • B. Negatively charged
  • C. Combination of all A., B. & C.
  • D. Neutral

Explanation: Atmospheric aerosols may acquire positive or negative charge, while many particles remain electrically neutral.

Correct answer: Combination of all A., B. & C.
  • A. 80
  • B. 100
  • C. 125
  • D. 150

Explanation: Noise inside a jet airliner during normal flight is commonly around 100 dB, although the exact level varies with aircraft type and seating…

Correct answer: 100
  • A. Ozone
  • B. Carbon dioxide
  • C. Hydrogen
  • D. None of these

Explanation: The ozone layer absorbs much of the Sun’s harmful ultraviolet radiation before it reaches Earth’s surface.

Correct answer: Ozone
  • A. Mercury
  • B. Fluoride
  • C. Lead
  • D. Arsenic

Explanation: Fluorosis results from long-term intake of excessive fluoride, producing mottling of teeth and, at higher exposure, skeletal damage.

Correct answer: Fluoride
  • A. Acts as a green house gas thereby raising earth's temperature
  • B. Causes asphyxia
  • C. Causes increase in sea level
  • D. Enhances the green house effect

Explanation: Carbon monoxide binds strongly with haemoglobin, forming carboxyhaemoglobin and preventing blood from carrying oxygen, so concentrations…

Correct answer: Causes asphyxia
  • A. Coagulation
  • B. Filtration
  • C. Preheating it
  • D. Anion exchanger

Explanation: Soluble silica is present as ionic or weakly ionised species and is removed effectively by a strong-base anion exchanger during…

Correct answer: Anion exchanger
  • A. 1
  • B. 7
  • C. 19
  • D. 82

Explanation: The stated permissible mercury concentration in blood is about 7 micrograms per 100 cc.

Correct answer: 7
  • A. Hydrogen
  • B. Acetylene
  • C. Carbon monoxide
  • D. Ammonia

Explanation: Acetylene has an exceptionally wide flammability range in air, approximately 2 to 81% by volume, so it can form explosive mixtures over a…

Correct answer: Acetylene
  • A. Iodine
  • B. Zinc
  • C. Iron
  • D. Bromine

Explanation: Iron salts oxidise to hydrated ferric compounds that deposit as reddish-brown stains on fabrics.

Correct answer: Iron
  • A. CO2
  • B. H2
  • C. CO
  • D. CH4

Explanation: Anaerobic digestion of sewage sludge in an Imhoff tank produces biogas, whose principal combustible component is methane.

Correct answer: CH4
  • A. Nitric acid
  • B. Sulphuric acid
  • C. Chlor alkali
  • D. Iron & steel

Explanation: Sulphuric acid manufacture can release sulphur dioxide, particularly from sulphur burning or sulphide-ore roasting, if gas conversion and…

Correct answer: Sulphuric acid
  • A. Industrial chimney exhaust
  • B. Photochemical reaction in polluted atmosphere
  • C. Automobiles exhaust
  • D. Burning of domestic fuel

Explanation: Automobile engines produce carbon monoxide when fuel burns incompletely, especially under fuel-rich conditions.

Correct answer: Automobiles exhaust
  • A. Bog iron
  • B. Limestone powder or alkalised alumina
  • C. Silica gel
  • D. Active carbon

Explanation: Alkalised alumina provides an alkaline surface that adsorbs acidic SO₂, while limestone can also capture it by reaction to form calcium…

Correct answer: Limestone powder or alkalised alumina
  • A. Underground burial in concrete containers
  • B. Pathological incineration
  • C. Pyrolysis
  • D. High temperature incineration

Explanation: Radioactive solids cannot be safely destroyed by ordinary incineration or pyrolysis because their radioactivity remains.

Correct answer: Underground burial in concrete containers