Advertisements
Advertisements
प्रश्न
Write a chemical equation to show the process of corrosion of iron.
Advertisements
उत्तर
In corrosion, oxidation of iron takes place.
Fe (s) → Fe2+ (aq) + 2e−
Iron supplies electrons at the edge of the droplet to reduce oxygen from the air.
O2 (g) + 2H2O (l) + 4e− → 4OH− (aq)
Within the droplet, the hydroxide ions react with the iron(II) ions and iron(II) hydroxide is precipitated.
Fe2+ (aq) + 2OH− (aq) → Fe(OH)2 (s)
Rust is then quickly produced by the oxidation of the precipitate.
4Fe(OH)2 (s) + O2 (g) → 2Fe2O3 • H2O (s) + 2H2O (l)
APPEARS IN
संबंधित प्रश्न
Why is an iron grill painted frequently?
Give the constituents and one use of brass.
What are the constituents of stainless steel?
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of:
(a) hydrated copper sulphate
(b) copper oxide
(c) basic copper carbonate
(d) copper nitrate
Name the metal which is a constituent of blood pigment?
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 ..................................................................
What is done to prevent corrosion of metals?
Answer the following question.
List two properties of alloys.
Give reason.
An iron article should be given a coat of paint
Give reason.
A wooden article should be polished.
Give reason for the following:
A suspension of rust is basic in nature.
Find the odd one out and give its explanation.
What is rust?
Observe the following figure and write the answer of the question.
- Which process is shown in the figure?
- Explain the chemical reaction shown in the figure.
- Write the reactions on anode and cathode.
State two conditions necessary for rusting of iron.
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
Alloys are homogeneous mixtures of a metal with a metal or nonmetal. Which among the following alloys contain non-metal as one of its constituents?
Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
Describe two changes that are harmful. Explain why you consider them harmful. How can you prevent them?
