High purity copper metal is obtained by:

1. carbon reduction

2. hydrogen reduction

3. electrolytic reduction

4. thermite process

Aluminothermic process is used for the extraction of metals, whose oxides are:

1. fusible

2. not easily reduced  by carbon

3. not easily reduced by hydrogen

4. strongly basic

Purest form of iron is:

1. cast iron

2. hard steel

3. stainless steel

4. wrought iron

Thomas slag is:

1. calcium silicate

2. calcium  phosphate

3. tricalcium phosphate and calcium silicate

4. calcium ammonium phosphate

Corundum is:

1. SrO₂

2. Al₂O₃

3. CaCl₂

4. Cu₂Cl₂

Heating of carbonate ores to remove carbon is called as:

1. roasting

2. calcination

3. smelting

4. fluxing

Sulphide ores are common for the metals:

1. Ag, Cu and Pb

2. Ag, Cu and Sn

3. Ag, Mg and Pb

4. Al, Cu and Pb

Which element occurs freely in nature?

1. Iodine

2. Sulphur

3. Phosphorus

4. Magnesium

Silver obtained by argentiferrous lead is purified by:

1. distillation

2. froth floatation

3. cupellation

4. reacting with KCN

Which process is not used in purification of bauxite?

1. Hall's method

2. Baeyer's method

3. Serpek's method

4. Frankland's method