Advertisements
Advertisements
प्रश्न
Give the constituents and one use of brass.
Advertisements
उत्तर
Brass is an alloy of copper and zinc. Composition of brass is copper (80 percent) and zinc (20 percent). Brass is used for making vessels and scientific instruments (e.g.microscope).
APPEARS IN
संबंधित प्रश्न
Write two methods of preventing the rusting of iron.
Choose the correct answer from the options given below:
Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as
A. Smelting
B. Ore-dressing
C. Calcination
D. Bessemerisation
What is anodising? Give its applications.
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 .............
Name any two metals which do not corrode easily.
What is the corrosion of iron known as?
What is meant by 'rusting of iron'? With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
Name five methods of preventing rusting of iron.
Name a common metal which is highly resistant to corrosion.
Mention two uses of the following metals and non-metals
Iron
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 ..................................................................
Rusting of iron : Fe2O3 : : corrosion of copper : ______
Write a molecular formula for rust.
Observe the following diagram and give answers.
- Name this method of prevention of corrosion.
- For prevention of which metal this method is used?
- What is used as anode in this method?
State two conditions necessary for rusting of iron.
Which among the following alloys contain mercury as one of its constituents?
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
