Advertisements
Advertisements
Question
A metal X which is resistant to corrosion is produced by the electrolysis of its molten oxide whereas another metal Y which is also resistant to corrosion is produced by the reduction of its oxide with carbon. Metal X can be used in powder form in thermite welding whereas metal Y is used in making cathodes of ordinary dry cells.
(a) Name the metals X and Y.
(b) Which of the two metals is more reactive : X or Y?
(c) Name one ore or metal X. Also write its chemical formula.
(d) Name one ore or metal Y. Also write its chemical formula.
(e) Name one alloy of metal X and one alloy of metal Y.
Advertisements
Solution
(a) Metal X is aluminium and metal Y is zinc.
Metal X or aluminium is resistant to corrosion and is produced by electrolysis of molten aluminium oxide. Aluminium is used in thermite welding.
Metal Y or zinc is also resistant to corrosion and is produced by reduction of zinc oxide with carbon (reducing agent). Zinc is widely used in making cathodes of ordinary dry cells.
(b) X (aluminium) is more reactive than Y (zinc). Aluminium is placed above zinc in the reactivity series.
(c) One ore of metal X (aluminium) is bauxite ore. The chemical formula of bauxite ore is Al2O3.2H2O.
(d) One ore of metal Y (zinc) is calamine ore. The chemical formula of calamine ore is ZnCO3.
(e) One alloy of metal X (aluminium) is magnalium, which consists of aluminium and magnesium. One alloy of metal Y (zinc) is brass, which consists of zinc and copper.
APPEARS IN
RELATED QUESTIONS
What is an alloy?
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
Write a chemical equation to show the process of corrosion of iron.
What is meant by galvanisation? Why is it done?
Explain why, iron sheets are coated with zinc.
Explain why, through aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
What is the corrosion of iron known as?
Give the constituents and one use of brass.
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
Name a common metal which is highly resistant to corrosion.
Name the metal which is a constituent of blood pigment?
Choose the correct alternative and rewrite the following:
Iron is _____________________.
Give reason for the following:
A suspension of rust is basic in nature.
Match the columns.
| Group A | Group B |
| 1) Electroplating | a) Pressure cooker |
| 2) Anodising | b) Silver plated spoons |
| c) Coating of tin on copper | |
| d) Coating of Zinc on iron |
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
The process of coating the surface of the metal with a thin layer of zinc is called ______
Give the equation for the formation of rust.
State two conditions necessary for rusting of iron.
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
