Viraf J. Dalal solutions for New Simplified Middle School Chemistry [English] Class 8 chapter 9 - Carbon & Its Compounds [Latest edition]

Differentiate between the two branches of chemistry – organic chemistry & inorganic chemistry with suitable examples.

State how carbon occurs in the free state and in the combined state.

Define the term ‘allotropy’. Give a reason why carbon exhibits allotropy.

Name two crystalline and four amorphous allotropes of carbon.

Compare the structure of the crystal of diamond & graphite with special reference to the reason for diamond being the hardest natural substance while graphite one of the softest. Compare the electrical & thermal conductivity of the two crystalline allotropes of carbon.

With reference to the structure of the two crystalline allotropes of carbon, state why diamond is inert or unreactive while graphite is comparably more reactive.

State the reasons for use of diamond as an item of jewellery.

State the reasons for use of graphite
(i) as a lubricant for heated machine parts, 
(ii) as a lining for crucibles used in manufacture of high grade steel, 
(iii) as an electrode in electroplating.

State in brief the transformation of vegetable matter to different types of coal varying in carbon content.

What are the uses of coal?

Give two uses for  the following:

coke

Give two uses for the following:

lampblack

‘Wood charcoal – an amorphous aliotrope of carbon reduces heated metallic oxides to metals.’ Give a balanced equation to support the statement.

Carbon dioxide occurs both in the free state and in the combined state.
State three methods how carbon dioxide is added to the atmosphere.

In the laboratory preparation of carbon dioxide by action of a dilute acid on a metallic carbonate give a balanced equation for the preparation.

In the laboratory preparation of carbon dioxide by action of a dilute acid on a metallic carbonate give a reason for:

(i) use of a washer bottle containing cone. H₂SO₄ in the preparation 
(ii) Not collecting the prepared gas over water 
(iii) Not using dilute sulphuric acid as a reactant in the preparation.

How would you prove experimentally that carbon dioxide does not support combustion.

How would you prove experimentally that is slightly acidic in nature.

Starting from carbon dioxide how would you obtain a weak acid. 
[Give balanced equations for the same]

Starting from carbon dioxide how would you obtain a fertilizer.
[Give balanced equations for the same]

Starting from carbon dioxide how would you obtain a highly poisonous gas.
[Give balanced equations for the same]

Starting from carbon dioxide how would you obtain a black particles of carbon.
[Give balanced equations for the same]

State how you would convert carbon dioxide to a metallic carbonate using a basic oxide e.g. sodium oxide. [Give a balanced equation]

‘When carbon dioxide is bubbled into lime water, the lime water turns milky and when bubbled in excess the milkiness disappears’. Give balanced equations to support the statement.

Explain the term ‘dry ice’. State its application.

Give three reasons why carbon dioxide finds application in fire extinguishers.

Using a magnesium ribbon, how would you prove that a given gas jar contains carbon dioxide.

State the function of cone, sulphuric acid in the laboratory preparation of carbon monoxide from oxalic acid.

Give reason why carbon monoxide is considered a highly poisonous gas. State why it is dangerous to sleep in a closed room with a fuel burning.

Give reason why carbon monoxide is considered a highly poisonous gas. State why it is dangerous to be in the vicinity of smokers.

Convert carbon monoxide to carbon dioxide using two different methods.

State how carbon monoxide finds application in the metallurgy of iron. [Give balanced equations for the same]

State how carbon monoxide finds application in preparation of an alcohol. [Give balanced equations for the same]

Name the following:

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

Name the following:

An allotrope of carbon used for the manufacture of coke.

Name the following:

An amorphous allotrope of carbon which floats on water.

Name the following:

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

Name the following:

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

Select the appropeiate option of the following statement:

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

Select the appropeiate option of the following statement:

The type of coal with the highest carbon conent.

Select the appropeiate option of the following statement:

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

Select the appropeiate option of the following statement:

A nitrogenous fertilizer obtained from carbon dioxide.

Select the appropeiate option of the following statement:

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

Give a balanced equation for the following conversion: [In one or two steps]

Coke to water gas.

Give a balanced equation for the following conversion: [In one or two steps]

Calcium bicarbonate to calcium nitrate using a dilute acid.

Give a balanced equation for the following conversion: [In one or two steps]

Lime water [soln. of calcium hydroxide] to calcium bicarbonate.

Give a balanced equation for the following conversion: [In one or two steps]

Carbon dioxide to carbon.

Give a balanced equation for the following conversion: [In one or two steps]

A metallic oxide to calcium carbonate.

Complete the statement by filling the blank with the correct word from the option.

The crystal of ________ is opaque to light and is a good conductor of heat.

Complete the statement by filling the blank with the correct word from the option.

A graphite-clay mixture baked at high temperature is used in making ______.

Complete the statement by filling the blank with the correct word from the option.

Adsorption capacity of wood charcoal is increased by passing ______ over wood charcoal, at high temperature.

Complete the statement by filling the blank with the correct word from the option.

______ Chemistry is the Chemistry of carbon compounds mainly of ‘Carbon’, ‘Hydrogen’ & ‘Oxygen’.

Complete the statement by filling the blank with the correct word from the option.

Sodium oxide combines with carbon dioxide to give _____

Give reason for the following:

Diamond & graphite are allotropic modifications of carbon.

Give reason for the following:

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

Give reason for the following:

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

Give reason for the following:

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

Give reason for the following:

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