(a) What is corrosion? Explain the conditions required for the rusting of iron, and describe three effective methods used to prevent corrosion. (b) Numerical Problem: A blast furnace process uses pure Hematite ore ($Fe2O3$) to extract iron metal according to the reaction: $$Fe2O3(s) + 3CO(g) ightarrow 2Fe(s) + 3CO2(g)$$
Calculate the maximum theoretical mass of pure iron (in grams) that can be extracted from $800 ext{ g}$ of pure Hematite ($Fe2O3$). (Given atomic masses: $Fe = 56 ext{ u}$, $O = 16 ext{ u}$)

Q: (a) What is corrosion? Explain the conditions required for the rusting of iron, and describe three effective methods used to prevent corrosion. (b) Numerical Problem: A blast furnace process uses pure Hematite ore ($Fe2O3$) to extract iron metal according to the reaction: $$Fe2O3(s) + 3CO(g) \rightarrow 2Fe(s) + 3CO2(g)$$\nCalculate the maximum theoretical mass of pure iron (in grams) that can be extracted from $800\text{ g}$ of pure Hematite ($Fe2O3$). (Given atomic masses: $Fe = 56\text{ u}$, $O = 16\text{ u}$)

Part (a): Corrosion and Prevention Corrosion:\nCorrosion is the process in which metals are gradually eaten away by the action of air, moisture, or chemicals (like acids) on their surface. Example: Rusting of iron, tarnishing of silver (formation of $Ag2S$), and formation of a green coating on copper ($CuCO3\cdot Cu(OH)2$). Conditions Required for Rusting of Iron: Presence of Air (Oxygen): Oxygen is necessary for oxidation of iron. Presence of Water/Moisture: Water vapor acts as a medium for the chemical reaction to form hydrated iron oxides ($Fe2O3\cdot xH2O$). Methods to Prevent Corrosion: Galvanization: Coating iron articles with a thin layer of zinc metal. Zinc protects iron because it is more reactive and oxidizes preferentially. Alloying: Mixing iron with other metals/non-metals to alter its properties (e.g., Stainless steel, made by mixing iron with chromium and nickel, does not rust). Painting, Greasing, or Oiling: Applying a protective coat on the metal surface prevents direct contact with air and moisture. --- Part (b): Numerical Solution Calculate Molar Mass of $Fe2O3$: Atomic mass of $Fe = 56\text{ u}$ Atomic mass of $O = 16\text{ u}$ $$\text{Molar mass of } Fe2O3 = (2 \times 56) + (3 \times 16) = 112 + 48 = 160\text{ g/mol}$$ Calculate Molar Mass of Iron ($2Fe$) produced: $$\text{Mass of } 2Fe = 2 \times 56 = 112\text{ g/mol}$$ Stoichiometric Relationship:\nFrom the chemical reaction: $$160\text{ g of } Fe2O3 \text{ yields } 112\text{ g of } Fe$$ Mass of Iron obtained from $800\text{ g}$ of $Fe2O3$: $$\text{Mass of } Fe = \left( \frac{112\text{ g}}{160\text{ g}} \right) \times 800\text{ g}$$ $$\text{Mass of } Fe = 0.7 \times 800\text{ g} = 560\text{ g}$$ Final Answer:\nThe maximum theoretical mass of pure iron extracted is $560\text{ g}$.

Question

(a) What is corrosion? Explain the conditions required for the rusting of iron, and describe three effective methods used to prevent corrosion. (b) Numerical Problem: A blast furnace process uses pure Hematite ore ($Fe2O3$) to extract iron metal according to the reaction: $$Fe2O3(s) + 3CO(g) ightarrow 2Fe(s) + 3CO2(g)$$
Calculate the maximum theoretical mass of pure iron (in grams) that can be extracted from $800	ext{ g}$ of pure Hematite ($Fe2O3$). (Given atomic masses: $Fe = 56	ext{ u}$, $O = 16	ext{ u}$)

Accepted Answer

Part (a): Corrosion and Prevention Corrosion:
Corrosion is the process in which metals are gradually eaten away by the action of air, moisture, or chemicals (like acids) on their surface. Example: Rusting of iron, tarnishing of silver (formation of $Ag2S$), and formation of a green coating on copper ($CuCO3\cdot Cu(OH)2$). Conditions Required for Rusting of Iron: Presence of Air (Oxygen): Oxygen is necessary for oxidation of iron. Presence of Water/Moisture: Water vapor acts as a medium for the chemical reaction to form hydrated iron oxides ($Fe2O3\cdot xH2O$). Methods to Prevent Corrosion: Galvanization: Coating iron articles with a thin layer of zinc metal. Zinc protects iron because it is more reactive and oxidizes preferentially. Alloying: Mixing iron with other metals/non-metals to alter its properties (e.g., Stainless steel, made by mixing iron with chromium and nickel, does not rust). Painting, Greasing, or Oiling: Applying a protective coat on the metal surface prevents direct contact with air and moisture. --- Part (b): Numerical Solution Calculate Molar Mass of $Fe2O3$: Atomic mass of $Fe = 56	ext{ u}$ Atomic mass of $O = 16	ext{ u}$ $$	ext{Molar mass of } Fe2O3 = (2 	imes 56) + (3 	imes 16) = 112 + 48 = 160	ext{ g/mol}$$ Calculate Molar Mass of Iron ($2Fe$) produced: $$	ext{Mass of } 2Fe = 2 	imes 56 = 112	ext{ g/mol}$$ Stoichiometric Relationship:
From the chemical reaction: $$160	ext{ g of } Fe2O3 	ext{ yields } 112	ext{ g of } Fe$$ Mass of Iron obtained from $800	ext{ g}$ of $Fe2O3$: $$	ext{Mass of } Fe = \left( \frac{112	ext{ g}}{160	ext{ g}} ight) 	imes 800	ext{ g}$$ $$	ext{Mass of } Fe = 0.7 	imes 800	ext{ g} = 560	ext{ g}$$ Final Answer:
The maximum theoretical mass of pure iron extracted is $560	ext{ g}$.