NACE 1 EXAM 2023/2024 CORRECT AND VERIFIED ANSWERS GRADED A+

NACE 1 EXAM 2023/2024 CORRECT AND VERIFIED ANSWERS GRADED A+ 1.The electrode of an electrochemical cell at which oxidation occurs? Anode 2. Electrons flow away from the ______ in the external circuit. Anode 3. Corrosion usually occurs and metal ions enter the solution at the ______? Anode 4. The electrode of an electrochemical cell at which reduction is the principal reaction? Cathode 4. Electrons flow towards the ______ of an electrochemical cell. Cathode 5. A technique to reduce the corrosion of a metal surface by making that surface the cathode of an electrochemical cell. Cathodic Protection 6 The deterioration of a material, usually a metal, that results from a reaction with the environment. Corrosion 7. In order for corrosion to occur, certain conditions and elements are essential. This combination of an anode, cathode, return path and electrolyte. Corrosion Cell 8. Localized corrosion of a metal surface at, or immediately adjacent to, an area that is shielded from full exposure to the environment because of close proximity of the metal surface of another material. Crevice Corrosion 9. A chemical substance or combination of substances that, when present in the environment, prevents or reduces corrosion. Corrosion Inhibitor 10. A chemical substance containing ions that migrate in the electric field. Electrolyte 11. A list of metals and alloys arranged according to their corrosion potentials in a given environment. Galvanic Series 12. Corrosion that is distributed more or less uniformly over the surface of a material. Generalized Corrosion 13. This occurs at discrete sites on the metal surface. Localized Corrosion 14. The oxide layer formed during hot fabrication or heat treatment of metals. Mill Scale 15. A reduction of the anodic reaction rate of an electrode involved in corrosion. Passivation 16. Localized corrosion of a metal surface that is confined to a small area and takes the form of cavities called pits. Pitting Corrosion 17. This connects the anode and cathode, allowing passage of electrons, generated at the anode, to the cathode. Return Path (Metallic Pathway) 18.1 - 2 - Define Corrosion: The deterioration of a material, usually a metal, that results from a reaction with the environment. 19.1 - 2 - What are the elements of a corrosion cell? This combination of an anode, cathode, return path and electrolyte. 20.1 - 2 - Describe what happens at the anode The part that corrodes, dissolves in electrolytes, dissolves in the form of positively charges ions, electrons generated are conducted to the cathode 21. 1 - 2 - What is the function of the electrolyte? to conduct ionic current, closes the loop in the corrosion cell, 22. 1 - 2 - What is the function of the metallic pathway? to connect the anode to the cathode and allow passage of electrons. 23. 1 - 2 - What is the galvanic series? a list of materials in order of their corrosion potentials, with the most easily corroded, or most active, at the top and the least active or corroded at the bottom. 24. 1 - 2 - What is passivation? ...The formation of a protective oxide film on the surface reducing its chemical activity and its ability to corrode. 25. 1 - 2 - The general rules of galvanic corrosion are? - When dissimilar metals are connected, the most active (or anodic) metals corrodes more rapidly, while the more noble metal is better protected and corrodes less rapidly. - As the potential difference between these two dissimilar metals increases, the rate of galvanic corrosion increases. - Corrosion rates increase as potential differences between metals increase. 26. 1 – 2 – Name at least 5 factors that effect the rate of corrosion. Oxygen, temperature, chemical salts, humidity and pollutants and acid gases. 27. 1 - 2 - General corrosion is: A uniform loss of material over the entire surface, easy to inspect and does not cause catastrophic failures.