Advertisements
Advertisements
प्रश्न
Give the constituents and one use of brass.
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
Tinning : Tin : : Galvanizing : _________
In one method of rust prevention, the iron is not coated with anything. Which is this method?
What is corrosion?
Name an alloy of copper. State its chemical composition and any one use.
Name a common metal which is highly resistant to corrosion.
A common metal which is highly resistant to corrosion is:
(a) iron
(b) copper
(c) aluminium
(d) magnesium
Mention two uses of the following metals and non-metals
Iron
Explain how the activity series accounts for each of the following:
tendency to corrosion
Compare roasting and calcination.
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
Write a short note on Alloying.
Write scientific reason.
Coins are made from metals and alloys.
Complete flow chart given below.
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.
The iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
| A process of forming a thick oxide of aluminium when aluminium is exposed to air. This coat makes it resistant to corrosion. Resistance can be improved by making a layer of oxide thinker. In this technique, the aluminium article is the anode, and the electrolyte is sulphuric acid. The anode reaction results in the formation of a black-coloured film of aluminium oxide on the anode. By putting appropriate dyes in the electrolytic solution, both coloured surface with the decorative finish is achieved. Kitchen articles like anodised such as pressure cookers, pans and frames of sliding windows are applications of this technique. |
- Name the anode and electrolyte used in this technique.
- How can we make aluminium articles made resistant to corrosion?
- Name the technique used to coat the aluminium articles.
