Question

(a) All ores are minerals but all minerals arenot ores. Justify the statement.
(b) What is galvanization?
(c) Give composition of brass and bronze.
(d) Explain roasting with the help of reaction.
(e) What do you mean by amalgam?

Answer 1

a) All ores are the minerals from which metals can be extracted commercially but all the minerals cannot be used to extract any metals e.g. bauxite is an ore of aluminium metal.
b)Galvanization is the process of applying a zinc coating on the surface of steel or iron materials.It is done to prevent the corrosion of the metals as the surface layer when comes in contact with air or moisture gets corroded.So molten zinc is used in the form of layer as corrosion resistant material.
c)Brass is an alloy of copper and zinc.Bronze is an alloy of copper,tin and zinc.
d)Roasting is the process of heating sulfide ore in the presence of hot air when sulfide is converted to its oxide and sulfur is released as sulfur dioxide.

e)Amalgam is a combination of metals like silver-22-32%,mercury-50%,tin -14%and copper-8%.