Iron is made inactive or passive by:

1. H₃PO₄

2. conc. HNO₃

3. conc. H₂SO₄

4. dil. HNO₃

The inner lining of a blast furnace is  made up of:

1. graphite bricks

2. silica  bricks

3. fire clay bricks

4. basic bricks

Roasting is generally carried out in case of :

1. Oxide ores

2. Sulphide ores

3. Silicate ores

4. Carbonate ores

Plumbo-solvency refers to:

1. oxidation of lead to lead oxide

2. oxidation of lead to red lead

3. dissolution of lead in water containing air

4. making lead wires by forcing heated metal through a die

Rutile is an ore of:

1. Ti

2. Zr

3. Mn

4. V

Which is not a mineral?

1. Mica

2. Peat

3. Quartz

4. Felspar

Alloy is an example of:

1. gel

2. aerosol

3. solid sol

4. emulsion

The second most common element on the earth is:

1. silicon

2. hydrogen

3. nitrogen

4. oxygen

Nickel is purified by thermal decomposition of its:

1. Hydride

2. Chloride

3. Azide

4. Carbonyl

In Serpek's process , by product obtained in the purification of bauxite is:

1. Al₂O₃

2. N₂

3. NH₃

4. none