As part of its food safety
program, USDA has simplified food safety rules into clean, separate, chill and cook.
Following these core four practices for food safety helps to prevent bacteria and
to reduce one’s risk of foodborne illness. The rule emphasize on washing of hands
and surfaces often, separating food substances to avoid cross-contamination, cooking
to the safe internal temperature and proper refrigeration of food.
Answer:
Explanation:
Oxygen gas and water must be present for iron to rust.
A region of the metal’s surface serves as the anode, where oxidation
occurs:
Fe(s) → Fe²⁺ (aq) + 2 e⁻
The electrons given up by iron reduce atmospheric oxygen to water at the cathode, which is another region of the same metal’s surface:
O₂ (g) + 4H⁺ (aq) + 4 e⁻ → 2 H₂O (l)
The overall redox reaction is:
2 Fe(s) + O₂(g) → 4H⁺(aq) + 2Fe²⁺ (aq) + 2 H₂O(l)
The Fe²⁺ ions formed at the anode are further oxidized by oxygen:
4 Fe²⁺ (aq) + O₂(g) 1 (4 + 2x) H₂O (l) → 2 Fe₂O₃ . xH₂O(s) + 8 H⁺(aq)
This hydrated form of iron(III) oxide is known as rust. The amount of water associated with the iron oxide varies, so we represent the formula as 2 Fe₂O₃ . xH₂O.
Answer:
D
Explanation:
by process known as photolysis
