All Free Chemical Engineering MCQs with Answers

• A. Hardening makes the steel more brittle
• B. High alloy steels contain more than 50% alloying element
• C. Both B. and C.
• D. 18/8 stainless steel is a magnetic steel

Explanation: High-alloy steels do not require more than 50% alloying elements, and 18/8 stainless steel is normally a non-magnetic austenitic steel.

• A. All A., B. and C.
• B. Causing metal embrittlement
• C. Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at
• D. high temperature
• E. Accelerating the rate of scaling

Explanation: Sulphur dioxide in hot furnace gases promotes scaling, can cause embrittlement, and may attack grain boundaries in susceptible steels at…

• A. 1 to10
• B. 1 to 8
• C. 1 to 15
• D. 0 to 10

Explanation: The Mohs hardness scale is numbered from 1 for talc to 10 for diamond. Therefore, the stated range is 1 to 10, not 0 to 10.

• A. Cork
• B. Glass
• C. Rubber
• D. Graphite

Explanation: Rubber is an elastomer, so it undergoes both elastic recovery and viscous deformation, giving it viscoelastic behaviour.

• A. Aqua regia
• B. Ferrous sulphate
• C. Hydrochloric acid (10%)
• D. None of these

Explanation: Aluminium is attacked by aqua regia and hydrochloric acid, while ferrous sulphate solution can also promote corrosion through chemical…

• A. Babbitt metal
• B. Monel
• C. Inconel
• D. Chlorinet - 2 alloy

Explanation: Monel, Inconel and Chlorimet-2 are nickel-containing corrosion-resistant alloys.

• A. 0.35 to 0.5
• B. 0.1 to 0.35
• C. 0.8 to 1.4
• D. 1 to 1. 5

Explanation: Medium-carbon steel is commonly classified as containing about 0.3 to 0.6% carbon; among the choices, 0.35 to 0.5% is the appropriate…

• A. Normalising
• B. Tempering
• C. Annealing
• D. None of these

Explanation: Tempering reheats hardened steel below its critical temperature, reducing excessive hardness and brittleness while improving toughness.

• A. Phenol
• B. Acetic acid
• C. Ammonia
• D. Formaldehyde

Explanation: Ammonia is normally transported in strong steel containers because it is volatile and is commonly handled as a pressurised liquefied gas.

• A. Do not require heat treatment for any of its applications
• B. Is tempered at 850°C
• C. Do not have good resilience properties
• D. Are used for leaf and coiled springs

Explanation: Silico-manganese steel combines strength, elasticity and good fatigue resistance, making it suitable for leaf springs and coiled springs.

• A. Wood
• B. Copper bearing steel
• C. Concrete
• D. Porcelain

Explanation: Molasses fermentation vessels for alcohol production are commonly made from copper-bearing steel, which provides suitable strength and…

• A. Aluminium
• B. Lead
• C. Iron
• D. Nickel

Explanation: Iron or mild steel is used for mercury containers because mercury does not readily amalgamate with iron, unlike aluminium, lead, nickel…

• A. Silicone rubber, teflon, porcelain and wood
• B. Nickel, monel, stainless steel and graphite
• C. Aluminium, copper, high silicon iron
• D. Brass, cast iron, mild steel and tin

Explanation: At 40°C, glacial acetic acid can attack brass, cast iron, mild steel and tin, making this group unsuitable.

• A. Steel
• B. Concrete
• C. Zircaloy
• D. Graphite

Explanation: A steel thermal shield is placed inside high-powered reactors to absorb radiation and heat, protecting the reactor walls or vessel from…

• A. Hydrochloric acid
• B. All A., B. and C.
• C. Chlorine (dry or wet)
• D. SO2 (dry or wet)

Explanation: Hydrochloric acid, sulphur dioxide and chlorine can all chemically attack or deteriorate wood, especially when moisture is present.

• A. Hot rolled
• B. Chrome carbon
• C. Cold rolled
• D. Stainless

Explanation: Bicycle-frame tubes are commonly made from cold-rolled steel because cold working gives a smooth finish, accurate dimensions and improved…

• A. Under stressing the specimen
• B. Rise in temperature
• C. Having notches in the specimen
• D. Having scratches on the surface

Explanation: Controlled understressing can increase fatigue strength through coaxing, which stabilizes the material against repeated loading.

• A. Toughness
• B. Creep limit
• C. Stiffness
• D. All A., B. & C.

Explanation: Oxide formation during atmospheric exposure can impair high-temperature strength by reducing the creep limit.

• A. Monel
• B. Graphite
• C. Stainless steel
• D. Kel-F and Teflon

Explanation: Stainless steel is unsuitable for aqueous hydrofluoric acid at 100°C because fluoride ions destroy its protective passive film and cause…

• A. Cast iron
• B. Monel
• C. Karbate
• D. Aluminium or chromium alloys (Cr > 18% for cold acid)

Explanation: Aluminium and chromium-rich alloys become protected by a passive oxide film in concentrated nitric acid, making them suitable storage…