Name the following:

1. A crystalline allotrope of carbon built up from a hexagonal unit.

2. An allotrope of carbon used for the manufacture of coke.

3. An amorphous allotrope of carbon which floats on water.

4. An acid formed when carbon dioxide is dissolved in water under pressure.

5. The gaseous product obtained when carbon monoxide is passed over heated iron [III] oxide.

Select the correct answer from A, B, C, D & E for each statement given below:

A: Anthracite

B: Diamond

C: Carbogen

D: Urea

E: Lampblack

1. An allotrope of carbon used as a tip for deep boring, drills.

2. The type of coal with the highest carbon content.

3. An allotrope of carbon, obtained by burning kerosene oil in a limited supply of air.

4. A nitrogenous fertilizer obtained from carbon dioxide.

5. A compound which finds use for a victim of carbon monoxide poisoning.

Complete the statements by filling the blanks with the correct word from the bracket.

1. The crystal of …………… [diamond/graphite] is opaque to light and is a good conductor of heat.

2. A graphite-clay mixture baked at high temperature is used in making …………… [lubricants/refractory crucibles]

3. Adsorption capacity of wood charcoal is increased by passing …………… [carbon dioxide/steam] over wood charcoal, at high temperatures.

4. …………… [organic/inorganic] Chemistry is the Chemistry of carbon compounds mainly of 'Carbon', 'Hydrogen' & 'Oxygen'.

5. Sodium oxide combines with carbon dioxide to give …………… [sodium carbonate/sodium bicarbonate]

Give reasons for the following:

1. Diamond & graphite are allotropic modifications of carbon.

2. It is dangerous to stand behind a running engine of a vehicle.

3. Both CO₂ & SO₂ turn lime water milky. Moist potassium permanganate paper, helps in distinguishing the two gases.

4. Carbon monoxide and not carbon dioxide is a highly poisonous gas.

5. Lime water finds application for testing both carbon dioxide & carbon monoxide gas individually.