Corrosion and Protection of Metals - Chapter 6
32 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is NOT a noble metal?

  • Gold
  • Copper (correct)
  • Platinum
  • Silver

    • What is the natural combined form of metals found in nature known as?

  • Ores (correct)
  • Alloys
  • Isotopes
  • Compounds

    • When exposed to gaseous atmosphere or reactive liquid medium, what do the surfaces of almost all metals begin to do?

  • Decay (correct)
  • Expand
  • Harden
  • Melt

    • What is the process called when metals are chemically converted to form new products due to the action of the surrounding medium?

    <p>Corrosion</p> Signup and view all the answers

    What does iron tend to revert to when exposed to an aqueous environment containing dissolved oxygen?

    <p>$Fe_2O_3$</p> Signup and view all the answers

    What are the new products formed during the chemical decay of metals usually in the form of?

    <p>Hydrated oxides, carbonates, sulphides, sulphates etc.</p> Signup and view all the answers

    What is the main cause of corrosion of metals according to the text?

    <p>Exposure to atmospheric gases like oxygen and carbon dioxide</p> Signup and view all the answers

    What type of film is formed on the surfaces of alkali and alkaline earth metals when attacked by oxygen?

    <p>Porous and non-continuous film</p> Signup and view all the answers

    What is the nature of the oxide film formed on heavy metals like copper, lead, and tin?

    <p>Continuous and non-porous film</p> Signup and view all the answers

    At higher temperatures, what happens to the oxide film formed on metals when exposed to oxygen?

    <p>It cracks, allowing further action of oxygen</p> Signup and view all the answers

    What is another term for immersed corrosion as mentioned in the text?

    <p>Wet oxidation</p> Signup and view all the answers

    Which type of corrosion involves electro-chemical reactions at the solid-liquid interface?

    <p>Immersed corrosion</p> Signup and view all the answers

    What is the primary role of oxygen in oxidation corrosion?

    <p>To directly attack and convert metal surfaces into oxides</p> Signup and view all the answers

    What occurs when the temperature of a metal increases in relation to oxidation corrosion?

    <p>The oxide film gets cracked, allowing further action of oxygen</p> Signup and view all the answers

    What is responsible for corrosion of metals to a greater extent under ordinary conditions?

    <p>Oxygen present in the medium</p> Signup and view all the answers

    What does atmospheric corrosion involve?

    <p>Exposure to atmospheric gases like oxygen and carbon dioxide</p> Signup and view all the answers

    What is the molecular weight range of high polymers?

    <p>Over 10,000</p> Signup and view all the answers

    What are the basic structural units of high polymers called?

    <p>Monomers</p> Signup and view all the answers

    What happens to the chains in thermoplasts when heated and compressed?

    <p>They can glide over each other</p> Signup and view all the answers

    How are thermoplasts' reaction to stress and temperature classified?

    <p>Based on ability to glide over each other</p> Signup and view all the answers

    What is the primary material property that allows thermoplasts to take the shape of a mould when heated and compressed?

    <p>Limited number of cross-links</p> Signup and view all the answers

    What is the name for the small organic molecules consisting of carbon atoms attached with other atoms, which form the basic structural units of high polymers?

    <p>Monomers</p> Signup and view all the answers

    What is the term for the process where two similar or dissimilar molecules react under the action of heat to form one larger molecule accompanied by the elimination of some simple molecules?

    <p>Condensation polymerization</p> Signup and view all the answers

    What is the name of the group of polymers composed of large molecules which tend to form spiral threads, somewhat like a coiled spring?

    <p>Elastomers</p> Signup and view all the answers

    Which type of polymerization occurs when the starting material is an unsaturated monomer and the polymer is produced by the union of monomeric units under suitable conditions?

    <p>Addition polymerization</p> Signup and view all the answers

    Which type of polymers are characterized by strong cross-links between the chains and once formed, cannot be remelted?

    <p>Thermosets</p> Signup and view all the answers

    What is the process where synthetic high polymers can be made by two main processes, addition polymerization and condensation polymerization?

    <p>Polymer synthesis</p> Signup and view all the answers

    What is the name of the polymerization that occurs via so-called organic condensation reactions and is known as?

    <p>Condensation polymerization</p> Signup and view all the answers

    What is the group of polymers typified by rubber, which stretches under slight stress but shows progressively greater resistance to distortion?

    <p>Elastomers</p> Signup and view all the answers

    What is the name of the important examples of thermosetting polymers, characterized by strong cross-links between the chains and cannot be remelted?

    <p>Phenolic and urea formaldehydes</p> Signup and view all the answers

    What is the name of the process where the starting material is an unsaturated monomer, and a chain reaction is propagated resulting in an addition polymer?

    <p>Addition polymerization</p> Signup and view all the answers

    What is the term for synthetic high polymers made by the union of monomeric units under suitable conditions?

    <p>Addition polymerization</p> Signup and view all the answers

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser