ELETROQUÍMICA OU QUÍMICA BÁSICA - QUESTAO 6 - ENEM 2022

ELECTROCHEMISTRY OR BASIC CHEMISTRY - QUESTION 6 - ENEM 2022 (Enem 2022) Nanotechnology is responsible for the improvement of several materials, including those that are impacted by the presence of pollutants and humidity in the atmosphere, which cause corrosion. The corrosion process is spontaneous and causes the deterioration of metals such as iron, which, in the presence of oxygen and water, undergoes oxidation, as illustrated by the chemical equation: One way to ensure the durability of the metal structure and its resistance to humidity is to deposit thin nanoceramic films based on zirconia (ZrO2) and alumina on the surface of the object to be protected. Sdf. CLEMENTE. G. A. B. F. et al. The use of hybrid materials or nanocomposites as anticorrosive coatings for steel. Química Nova, n. 9, 2021 (adapted). This nanotechnology applied to corrosion protection is based on: a) cathodic protection, which uses a highly reducing metal. b) use of sacrificial metals, which oxidize in place of iron. c) passivation of iron, which is coated with its own oxide. d) barrier effect, which prevents contact with the oxidizing agent. e) galvanization, which uses other metals with a lower reduction potential. (Enem 2022) Nanotechnology is responsible for the improvement of several materials, including those that are impacted by the presence of pollutants and humidity in the atmosphere, which cause corrosion. The corrosion process is spontaneous and causes the deterioration of metals such as iron, which, in the presence of oxygen and water, undergoes oxidation, as illustrated by the chemical equation: One way to ensure the durability of the metal structure and its resistance to humidity is to deposit thin nanoceramic films based on zirconia (ZrO2) and alumina on the surface of the object to be protected. Sdf. CLEMENTE. G. A. B. F. et al. The use of hybrid materials or nanocomposites as anticorrosive coatings for steel. Química Nova, n. 9, 2021 (adapted). This nanotechnology applied to corrosion protection is based on (a) cathodic protection, which uses a strongly reducing metal. b) use of sacrificial metals, which oxidize in place of iron. c) passivation of iron, which becomes coated with its own oxide. d) barrier effect, which prevents contact with the oxidizing agent. e) galvanization, which uses other metals with lower reduction potential.