Question

Figure 4 Question 7 (1 point) In Part III. Natural/Treated Water, you had to investigate the impact of open and closed systems on corrosion rate. Choose the statement that best explains the plot in Figure 4. Closed system a) In an open system, the heat causes a protective film to form over the surface of the metal. Corrosion rate (cm/year) Ob) In a closed system, the heat dissolves additional oxygen at higher temperatures. O Open system c) In hot water (regardless of temperature) more oxygen will dissolve than cold water. 20 100 120 d) In an open system, the dissolved oxygen escapes from solution more easily at higher temperatures. 40 60 80 Temperature (°C) Effect of oxygen on corrosion of steel e) In a closed system, the dissolved oxygen escapes from solution more easily at higher temperatures. https://corrosion-doctors.org Carrosion-by-Water/Constituents.htm

Answer 1

Dissolved oxygen destroys protective film and leads to corrosion. However, at higher temperatures in an open system the dissolved oxygen escapes from solution more easily. Therefore, you can see a drop in corrosion rate as temperature is increased beyond 65°C in open system. Option (d)