Question

give the method of preparation importance proparties and usese of carbon dioxide​

Answer 1

Answer:

Preparation of Carbon dioxide

(1) In the laboratory, carbon dioxide is prepared by the action of calcium carbonate with dilute hydrochloric acid.

CaCO3 + dil 2HCl → CaCl2 + CO2↑ + H2↑

(2) The combustion of carbon or methane produce carbon dioxide

C + O2 → CO2 + Heat

CH4 + 2O2 → CO2 + 2H2O

(3)The decomposition of carbonate salts like calcium carbonate or magnesium carbonate produces carbon dioxide.

CaCO3 → CaO + CO2

MgCO3 → MgO + CO2

(4) When metallic carbonates or metallic bicarbonates react with sulphuric acid, they form carbon dioxide.

Na2CO3 + H2SO4 → Na2SO4 + H2O + CO2

2 NaHCO3 + H2SO4 → Na2SO4 + 2 H2O + 2 CO2

Carbon dioxide is also formed in the process of fermentation as a by product.

Physical properties

Colourless and odourless gas with a sour taste.

Slightly soluble in water.

Heavier than air.

Solidifies at room temperature and 70 atmospheres pressure.

Solid CO2 is called Dry ice

Chemical properties

CO2 Reacts with water to form carbonic acid.

CO2 + H2O → H2CO3

CO2 Reacts with sodium hydroxide to form sodium carbonate. Excess carbon dioxide produces sodium bicarbonate.

CO2 + 2NaOH → Na2CO3 + H2O

Na2CO3 + H2O + CO2 → 2NaHCO3

CO2 Reacts with calcium hydroxide to form calcium carbonate and water.

Ca(OH)2 + CO2 → CaCO3 + H2O

CO2 Reacts with metals to form metallic oxides.

2Mg + CO2 → 2MgO + C

CO2 Reacts with non-metals to form carbon monoxide.

C + CO2 → 2CO

Uses

To prepare soft drinks and soda, in fire extinguishers, as a refrigerating agent, to prepare several chemicals like urea, washing soda and baking soda, to preserve food.

Helps to maintain the temperature of the earth’s surface. Used in welding to control corrosion

Answer 2

TOPIC:- CARBON DIOXIDE

Required answer:-

‎ ‎ ‎ ‎ ‎ Let's divide the methods of preparation of carbon dioxide into two categories as general methods and laboratory method.

General methods of preparation of CO₂ are as follows:

1. Burning of charcoal/coke: When charcoal or coke is burnt in adequate supply of air, it enhances the level of carbon dioxide. This reaction is highly exothermic.

$\: \: \: \: \: \: \: \: \: \: \sf{C+O_2 \longrightarrow CO_2+Q}$

2. Thermal decomposition of metal carbonates and bicarbonates: All carbonates except those of sodium (Na) or Potassium (K) on heating evolve carbon dioxide along with the formation of metal oxide.

$\: \: \: \: \: \: \: \: \sf{CaCO_3 \longrightarrow CaO+CO_2}$

And bicarbonates on strong heating evolve carbon dioxide along with the formation of the corresponding carbonate and water.

$\: \: \: \: \sf{NaHCO_3 \longrightarrow Na_2CO_3+H_2O}$

3. Action of dilute mineral acids on carbonates and bicarbonates: Dilute Hydrochloric acid (HCl) or Sulphuric acid (H₂SO₄) when added to the carbonate or bicarbonate salt, neutralization takes place with the liberation of carbon dioxide gas.

$\sf{Na_2CO_3+H_2SO_4 \longrightarrow Na_2SO_4+CO_2+H_2O} \\ \: \sf{NaHCO_3+HCl \longrightarrow NaCl+H_2O+CO_2}$

The laboratory method of CO₂ preparation is as follows:

‎ ‎ ‎ ‎ ‎ ‎Marble chips contains calcium carbonate which, on the addition of dilute hydrochloric acid, releases CO₂. With this principle, the preparation is performed by taking marble chips in a conical flask. A two-holder rubber cork is introduced into this. Through one hole, a thistle funnel is inserted and through another hole, a delivery tube is inserted. Dilute hydrochloric acid is added dropwise through the thistle funnel. CO₂ gas generated during the reaction comes out through the delivery tube, which can be collected by the upward displacement of air since it is heavier than air. Diagram has been attached for clarification!

★ Physical properties of CO₂:

• It's colourless.
• It has no characteristic smell.
• It's heavier than air.
• It's highly soluble in water.
• It's acidic.
• It has a boiling point of –78.5°C.

★ Chemical properties of CO₂:

• It's non-combustible.
• Neutralization takes place during it's reaction with alkalis.
• It turns lime water milky during it's reaction with lime water.
• It acts as a reducing agent.

★Uses of Carbon dioxide:

‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎Apart from being the natural and indispensable raw material for photosynthesis, CO₂ finds many important applications in various fields. Some are listed below.

• It is used for the hardening of mortars.
• It is used to stimulate respiratory system.
• It is used in soft drinks or aerated drinks.
• Solid carbon dioxide which is called as dry ice is used as a refrigerant.
• It is used in fire extinguishers to put off fires.
• It is extensively used in the production of industrial compounds, such as washing soda, baking soda, white lead, etcetera.

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