State briefly the principles which serve as basis for the following operations in metallurgy Refining by liquation.

State which of the following is correct

Write the chemical reactions which take place in the following operations: Isolation of zinc from blend.

Write the chemical reactions which take place in the following operations: Electrolytic reduction of Al_2O_3 .

Describe the underlying principle of each of the following metal refining methods. Electrolytic refining of metals.

State with reasons, whether the following algebraic operations with scalar and vector physical quantities are meaningful: (a) adding any two scalars, (b) adding a scalar to a vector of the same dimensions, (c) multiplying any vector by any scalar, (d) multiplying any two scalars, (e) adding any two vectors, (f) adding a component of a vector to the same vector.