Free Chemical Process Principles MCQs with Answers

• A. Stratosphere
• B. Troposphere
• C. Thermosphere
• D. Mesosphere

Explanation: The troposphere contains most of the atmosphere's mass, water vapour and ground-level pollutant emissions, so pollutants are concentrated…

• A. Thermosphere
• B. Troposphere
• C. Stratosphere
• D. Mesosphere

Explanation: Supersonic aircraft generally cruise in the stratosphere, where their exhaust releases pollutants at high altitude.

• A. Dissolved oxygen
• B. Turbidity
• C. Phenol
• D. Silica

Explanation: Silica is especially harmful in high-pressure boilers because it forms hard scale and can volatilise, causing deposits on turbine blades.

• A. Separation
• B. Anaerobic decomposition
• C. Aerobic decomposition
• D. None of these

Explanation: A septic tank retains solids and provides oxygen-free conditions in which microorganisms anaerobically decompose the settled organic…

• A. Radioactive
• B. Organic
• C. Inorganic
• D. None of these

Explanation: Electroplating, blast-furnace and coal-mining effluents mainly contain inorganic pollutants such as metal ions, acids, alkalis and mineral…

• A. Fumes
• B. Mists
• C. Smoke
• D. Aerosols

Explanation: Aerosols are very small solid or liquid particles suspended in a gas, often remaining airborne and travelling with wind.

• A. Aerobic
• B. Saprophytic
• C. Anaerobic
• D. Parasitic

Explanation: Trickling filters expose sewage to air as it passes over a microbial film, so aerobic bacteria carry out most of the biological oxidation.

• A. Catalytically convert SO2 to SO3 in
• B. Reduce SO2 content in
• C. Increase the dew point of
• D. None of these

Explanation: Limestone, mainly calcium carbonate, reacts with sulphur dioxide in the boiler or flue-gas system to form calcium sulphite or sulphate.

• A. Natural aeration of water stream
• B. Photosynthetic action of algae
• C. Both A. & B.
• D. Neither A. nor B.

Explanation: Dissolved oxygen is replenished naturally across the air-water interface and also produced by algae through photosynthesis when light is…

• A. Reduction in working efficiency of manpower
• B. Fatigue
• C. High breathing rate
• D. All A., B. & C.

Explanation: Excessive workplace heat imposes thermal stress, causing fatigue, reduced physical efficiency and an increased breathing rate as the body…

• A. All A., B. and C.
• B. Anaemia
• C. Nervous system disorder
• D. Blood poisoning

Explanation: Lead exposure can produce systemic toxicity, including impaired haemoglobin formation and anaemia, while also damaging the nervous system.

• A. Aluminium sulphate
• B. Chloramine
• C. Hydrated lime
• D. Ferrous sulphate

Explanation: Aluminium sulphate, ferrous sulphate and hydrated lime are used as chemical coagulants in water treatment.

• A. Carbonates
• B. Bi-carbonates
• C. Iron & manganese
• D. Arsenic

Explanation: Dissolved iron and manganese oxidise or precipitate as coloured compounds, producing a red, brown or blackish appearance in water.

• A. 1
• B. 4
• C. 8
• D. 12

Explanation: Atmospheric water vapour is highly variable and can range from nearly zero to about 4% by volume in the troposphere.

• A. Suspended inorganic matter
• B. Dissolved solids
• C. Floating solids
• D. Dissolved gases

Explanation: Turbidity is caused mainly by suspended particles that scatter light, such as clay, silt and other finely divided matter.

• A. Acceleration
• B. Idle running
• C. Cruising
• D. Deceleration

Explanation: Carbon monoxide is formed by incomplete combustion, which is especially severe during idling because the engine operates with a relatively…

• A. Respiratory disease (e.g. asthma)
• B. Retardation in crop growth
• C. Asphyxiation (suffocation) leading to death
• D. Damage to building materials like marble

Explanation: Carbon monoxide binds strongly to haemoglobin and forms carboxyhaemoglobin, preventing blood from carrying enough oxygen.

• A. Filtration
• B. Disinfection
• C. Sedimentation
• D. Coagulation

Explanation: Alum hydrolyses in water to form gelatinous aluminium hydroxide flocs, which enmesh and destabilise suspended particles.

• A. Sulphur dioxide
• B. Photochemical smog
• C. Ozone
• D. All A., B. & C.

Explanation: Sulphur dioxide is emitted directly from fuel combustion and is therefore a primary pollutant.

• A. Embrittlement & decrease of folding resistance of paper
• B. Cracking of rubber products
• C. Fading of dye on textiles
• D. Damage of electrical insulator on high tension power line

Explanation: Ozone is a powerful oxidising agent that attacks the unsaturated bonds in rubber, producing surface cracks and loss of elasticity.