Free Chemical Process Principles MCQs with Answers

• A. Cancer
• B. Dermatitis (skin disorder)
• C. Asphyxiation (suffocation)
• D. Asthma

Explanation: Carcinogens are agents capable of initiating or promoting uncontrolled cell growth, so prolonged exposure can cause cancer.

• A. 35
• B. 75
• C. 95
• D. 105

Explanation: The commonly quoted WHO recommended maximum for industrial noise in this type of question is about 75 dB.

• A. Lime
• B. Uranium ore
• C. Iron ore
• D. Coal

Explanation: Pneumoconiosis is a group of lung diseases caused by inhaled mineral dust, and coal dust produces the well-known coal-worker form.

• A. 10000 to 100000
• B. 3000 to 6000
• C. 6000 to 9000
• D. 1000 to 2000

Explanation: A very high TLV, around 10,000 to 100,000 ppm, is associated with gases considered relatively non-toxic in ordinary industrial exposure…

• A. 75
• B. 95
• C. 120
• D. 140

Explanation: Busy buses and subway trains commonly produce noise near 95 dB, a level high enough for prolonged exposure to threaten hearing.

• A. Coal
• B. Iron
• C. Silica
• D. None of these

Explanation: Siderosis, sometimes called iron-dust disease, results from inhalation and deposition of iron particles in the lungs.

• A. Biological treatment of wastes
• B. Reduction of excessive flow in sewers
• C. Sludge disposal
• D. None of these

Explanation: In wastewater practice, sludge lagooning means placing sludge in shallow lagoons for storage, drying, and partial stabilization, so it is…

• A. Automobile exhaust
• B. Flue gas of coal based power plant
• C. Exhaust of nitric acid plant
• D. Exhaust of sulphuric acid plant

Explanation: PAN is a secondary photochemical pollutant associated with automobile exhaust because vehicle hydrocarbons and nitrogen oxides form PAN in…

• A. Deforestation
• B. All A., B. and C.
• C. Increased transportation activity
• D. Rapid industrialisation

Explanation: Deforestation removes carbon dioxide-absorbing vegetation, while industry and transport add greenhouse gases through fuel combustion.

• A. Undesirable plant growth
• B. Non biodegradable foam
• C. Explosion
• D. Corrosion

Explanation: Volatile liquids such as gasoline and ether can produce flammable vapour-air mixtures inside sewers.

• A. Carbon monoxide
• B. Petrol vapor
• C. Hydrogen
• D. Acetylene

Explanation: Acetylene has an exceptionally broad flammability range, approximately 2.5% to 81% in air.

• A. All A., B. and C.
• B. Poor quality of fuel and improper mixing of fuel & combustion air
• C. Poor design & overloading of furnace
• D. Insufficient supply of combustion air and insufficient time for combustion

Explanation: Smoke forms when fuel does not burn completely, commonly because of inadequate air, poor mixing, insufficient time, poor fuel quality, or…

• A. July
• B. December
• C. June
• D. September

Explanation: World Environment Day is observed annually on 5 June. It is a United Nations observance focused on environmental awareness and action.

• A. Alum
• B. Bleaching powder
• C. Copper sulphate
• D. Activated carbon

Explanation: Activated carbon adsorbs many dissolved organic compounds responsible for unpleasant taste and odour.

• A. Cooling and freezing of water kills the bacteria present in it
• B. With increasing boiler operating pressure of steam, the maximum allowable concentration of
• C. silica in feed water goes on decreasing
• D. Dissolved oxygen content in high pressure boiler feed water should be nil

Explanation: Cooling or freezing does not reliably kill all bacteria, so statement a is wrong.

• A. Scale formation
• B. Dental cavities
• C. Water-borne disease
• D. Corrosion

Explanation: Fluoride at a controlled low concentration strengthens developing tooth enamel and reduces dental cavities.

• A. 0.001
• B. 0.1
• C. 1
• D. 5

Explanation: Mercury is highly toxic and its permissible concentration in drinking water is about 0.001 ppm.

• A. Discoloration of bathroom fixtures
• B. Reduction in its dissolved oxygen content
• C. Temporary hardness
• D. None of these

Explanation: Iron and manganese oxidise or precipitate as coloured deposits, producing staining and discoloration of bathroom fixtures.

• A. Undesirable plants growth
• B. Depletion of oxygen
• C. Fire hazards
• D. Explosion hazards

Explanation: Soluble organic matter is consumed by microorganisms, whose respiration uses dissolved oxygen and thereby depletes it.

• A. Cancer
• B. Asthma
• C. Silicosis
• D. Fluorosis (bone disease)

Explanation: Cement and limestone dust can contain respirable crystalline silica, whose long-term inhalation causes silicosis, a serious fibrotic lung…