Corrosion Science MCQ
Corrosion Science MCQ, Multiple Choice Questions on Corrosion Science, Science of Corrosion MCQ, Engineering Chemistry MCQ, Engineering MCQ, Corrosion MCQ Questions And Answers, Corrosion Engineering MCQ (Multiple Choice Questions), corrosion of a pipe MCQ, MCQ on corrosion engineering chemistry
Multiple-choice Questions
Q.1. Corrosion is an example of
- Oxidation
- Reduction
- Electrolysis
- Erosion
Answer: Oxidation
Q.2. Chemically, the rust is
- Fe2O3
- FeO · Fe2O3
- Fe2O3 · xH2O
- FeO · xH2O
Answer: Fe2O3 · xH2O
Q.3. The metal which is protected by a layer of its own oxide
- Cu
- Fe
- Au
- Al
Answer: Al
Q.4. The corrosion caused by the direct chemical action of environmental gases or anhydrous liquids on the metal surfaces is called
- Dry corrosion
- Wet corrosion
- Pitting corrosion
- Electrochemical corrosion
Answer: Dry corrosion
Q.5. Which of the following factors does not govern the rusting of iron?
- Presence of air
- Presence of moisture
- Presence of electrolytes in water
- Presence of impurities of more electropositive metals in iron
Answer: Presence of impurities of more electropositive metals in iron
Q.6. In galvanic corrosion
- More metal gets corroded
- Less noble metal gets corroded
- The metal having a higher standard reduction potential gets corroded
- The metal placed lower in the electrochemical series get corroded
Answer: Less noble metal gets corroded
Q.7. In electrochemical corrosion
- Anode undergoes oxidation
- Cathode undergoes oxidation
- Both undergo oxidation
- None undergoes oxidation
Answer: Anode undergoes oxidation
Q.8. In differential aeration corrosion
- Poor oxygenated part acts as anode
- Rich oxygenated part acts as anode
- Poor oxygenated part acts as anode
- Metal as a whole acts as cathode
Answer: Poor oxygenated part acts as anode
Q.9. The localized attack of a corroding environment leading to the formation of holes in an otherwise relatively unattacked surface of a metal is called
- Water-line corrosion
- Pitting corrosion
- Concentration cell corrosion
- Wet corrosion
Answer: Pitting corrosion
Q.10. Water-line corrosion is enhanced by the presence of
- Hydroxides
- Chlorides
- Carbonates
- Silicates
Answer: Chlorides
Q.11. Caustic embrittlement is a particular case of
- Pitting corrosion
- Dry corrosion
- Stress corrosion
- Wet corrosion
Answer: Stress corrosion
Q.12. To protect the buried pipeline from corrosion is connected to Mg piece through a wire. This process is called as
- Impressed current cathodic protection
- Galvanic protection
- Sacrificial anodic protection
- Sacrificial cathodic protection
Answer: Sacrificial anodic protection
Q.13. In an electrochemical series, the metal at the top is
- Most noble
- Most stable
- Most active
- Most protective
Answer: Most active
Q.14. Galvanizing is the process of coating iron with
- Mg
- Cu
- Zn
- Ni
Answer: Zn
Q.15. Corrosion of zinc metal containing an impurity of copper is called
- Water line corrosion
- Moist corrosion
- Stress corrosion
- Galvanic corrosion
Answer: Galvanic corrosion
Q.16. The anodic coating protects underlined metal
- Due to its higher reduction potential
- Due to its lower reduction potential
- Due to its noble nature
- Due to its higher oxidation potential
Answer: Due to its higher oxidation potential
Q.17. Addition of hydrazine-hydrate to the corrosive environment
- Retard anodic reaction
- Retard cathodic reaction by consuming dissolved oxygen
- Prevents diffusion of protons to cathode
- Increases hydrogen overvoltage
Answer: Retard cathodic reaction by consuming dissolved oxygen
Q.18. In general, corrosion is maximum when the pH of the corroding medium is
- Above 7.0
- Equal to 7.0
- Below 7.0
- Equal to 1.0
Answer: Below 7.0
Q.19. The process of covering steel with zinc to prevent it from corrosion is called
- Galvanizing
- Tinning
- Electroplating
- Electroless plating
Answer: Galvanizing
Q.20. Acid pickling of steel is carried out by dipping the steel in
- Dilute Hcl
- Dilute H2SO4
- Conc H2SO4
- Dil HNO3
Answer: Dilute H2SO4
Q.21. During galvanization, the function of flux ammonium chloride is
- To prevent oxide formation, on molten zinc
- To prevent reduction of molten zinc
- To acts as a barrier
- None of these
Answer: To prevent oxide formation, on molten zinc
Q.22. In electroplating, the object to be protected from corrosion is made as
- Anode
- Cathode
- Both anode and cathode
- None of the above
Answer: Cathode
Q.23. The oxygen carrier of the paint is called
- Drier
- Pigment
- Thinner
- Extenders
Answer: Drier
Q.24. In Electroless plating, the base metal article is immersed in a solution of
- More active metal salt
- More noble metal salt
- Any one of these
- None of the above
Answer: More noble metal salt
Q.25. An inhibitor which when added in small quantities to an aqueous corrosive environment
- Effectively decreases the corrosion of a metal
- Increases the corrosion of a metal
- No effect on corrosion of metal
- Increases the corrosion nature of the environment
Answer: Effectively decreases the corrosion of a metal
Q.26. The cathodic inhibitors slow down the corrosion reaction by decreases
- Diffusion of hydrated H+ ion to the cathode
- Diffusion of cl- ions to the cathode
- Diffusion of hydrated H+ ion to the anode
- None of the above
Answer: Diffusion of hydrated H+ ion to the cathode
Q.27. In cathodic coating, base metal is coated with
- More noble metal
- Less noble metal
- More active metal
- Having more reduction potential
Answer: More noble metal
Q.28. In Impressed current cathodic protection, the anode is placed in backfill because
- To slow down the rate of corrosion reaction
- To increases the rate of reaction
- To increase the electrical contact with the surrounding soil
- None of the above
Answer: To increase the electrical contact with the surrounding soil
Q.29. The rate of corrosion is more when
- Anodic area is large
- Anodic area is small
- Athodic area is small
- None of the above
Answer: Anodic area is small
Q.30. According to the pilling-Bedworth rule, Greater is the specific volume ratio
- More is the oxidation corrosion
- Lesser is the oxidation corrosion
- More is the reduction corrosion
- None of the above
Answer: Lesser is the oxidation corrosion