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प्रश्न
Describe two changes that are harmful. Explain why you consider them harmful. How can you prevent them?
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उत्तर
1. Rusting of Iron:
- Why Harmful: Rusting weakens iron and steel structures, leading to potential failures and increased maintenance costs.
- Prevention: Apply protective coatings like paint or use galvanization (coating with zinc) to prevent exposure to moisture and oxygen.
2. Food Spoilage:
- Why Harmful: Spoiled food can cause food poisoning and waste valuable resources.
- Prevention: Store food properly in cool, dry places, use refrigeration, and adhere to proper hygiene practices to slow down spoilage.
APPEARS IN
संबंधित प्रश्न
State two conditions for the rusting of iron.
Fill in the following blank with suitable word:
The process of depositing a thin layer of zinc on iron articles is called .............
What is corrosion?
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
Name the metal which is a constituent of plant pigment?
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
When Fe2+ ions migrate from anode region they react with ................... to form Fe3+ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.
`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
A way to prevent rusting ..................................................................
Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.
Give a reason why rust turns moist red litmus blue.
Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.
The substance not likely to contain CaCO3 is:
