Prabin Kalikote

We know, fire extinguisher has a red metallic vessel containing a sodium bicarbonate solution and a bottle of sulphuric acid. When we need carbon dioxide gas to extinguish a fire, the vessel is inverted. Afterwards, the bottle of concentrated sulpheric acid strikes against the floor. The plug of the acid bottle falls down and and comes in contact with the sodium bicarbonate solution. When those chemical react together, they give carbon dioxide...

The uses of carbon dioxide gas are:
        - Green plants use CO₂ during photosynthesis.
        - It is used on fire extinguishers.
        - It is used to manufacture fertilizers.
        - It is used to make soft as well as hard drinks.
        - It used in carbonation process to purify sugarcane juice.

We all know, CO₂ gas is acidic in nature and water is neutral. When a mixture of CO₂ and H₂O is made the mixture will have acidic PH. which stimulates the taste buds with sour taste.

When Ca(HCO₃)₂ solution is heated, it gives calcium carbonate, water and CO₂.
                            Ca(HCO₃)₂ -------------> CaCO₃ + H₂O + CO₂

A balloon filled with CO₂ left free in the air will fall on the surface of the land because CO₂ cause it to fall due to its higher density than that of air.

The ribbon burns in CO₂ gas with dazzling light.

Lime water turns milky in color due to the formation of insoluble calcium carbonate (CaCO₃).
                            CO₂ + Ca(OH)₂ -------------> CaCO₃ + H₂O

Dry ice is the solid substance formed when CO₂ gas is cooled to below -78c.
        - It is used as a refrigerant to preserve foods.

We all know, carbon dioxide gas is heavier than air which cause it to flow to the lower surface. Therefore, carbon dioxide gas is found in lower surface like deep wells, mines, caves, etc.

Carbon dioxide gas is collected in the gas jar by the downward of air because it is heavier than air which cause it to flow to the surface.

When carbon dioxide is passed in lime water for a long time, the milky color disappears slowly due to the formation of water soluble calcium bicarbonate [Ca(HCO₃)₂].
                                CaCO₃ + H₂O + CO₂ --------> Ca(HCO₃)₂

When we pass CO₂ in lime water, it becomes milky white due to the formation of insoluble calcium carbonate (CaCO₃).

For commercial purpose, carbon dioxide gas is manufactured by heating calcium carbonate. During this process, calcium oxide i.e. lime or quick lime is also produced.
                            CaCO₃ -------------> CaO + CO₂

Any 3 chemical properties of carbon dioxide gas are:
        - CO₂ reacts with water and gives carbonic acid.
                    CO₂ + H₂O ----------> H₂CO₃
        - Green plants concert solar energy into chemical energy by photosynthesis. In this process CO₂ and water react to give starch and oxygen.
...

Any 4 physical properties of CO₂ gas are:
        - It is colorless, odorless and tasteless gas.
        - It is heavier than air.
        - It is acidic in nature.
        - It is neither combustible nor a supporter of combustion.
        - It is soluble in wader and produce carbonic acid when dissolved in water.

The precautions needed during the laboratory preparation of CO₂ are:
        - The apartus should be made air tight.
        - The Lower end of delivery tube should not touch the solution within the woulfe's bottle.
        - The lower end of thistle funnel should be dipped in the solution.
        - Carbon dioxide is collected in the gas jar by the upward...

The different methods to test the carbon dioxide are:
        - Putting the burning matchstick into the jar containing CO₂. If it extinguishes.
        - When CO₂ is passed through lime water, it turns milky white due to the formation of insoluble CaCo₃. When CO₂ is passed in lime water for long time, the milky color disappears due to the formation of soluble Ca(HCO₃)₂.
        - CO₂ turns...

In the laboratory, carbon dioxide gas is prepared by the reaction of dilute hydrochloric acid with calcium carbonate (limestone or marble).
                                CaCO₃ + 2HCl ----------> CaCl₂ + H₂O + CO₂

When a glass rod is dipped in conc. HCl is brought in contact with ammonia gas, it forms a white fume of ammonium chloride (NH₄Cl).
                            HCl + NH₃ ------------> NH₄Cl

Ammonia gas prepared by heating a mixture of NH₄CL and CA(OH)₂.
                    2NH₄Cl + Ca(OH)₂ ---------> CaCl₂ + 2H₂O + 2NH₃

The uses of ammonia gas are:
        - It is used to manufacture chemical fertilizers.
        - Liquid ammonia is used in refrigerators.
        - It is used to develop blueprint of maps.
        - It is used to make medicines.
        - It is used as laboratory reagent.

Urea is produced when ammonia and carbon dioxide react together at about 1500C under certain pressure (30 atom).
                                2NH₃ + CO₂ ----------> NH₂ - CO - NH₂ + H₂O

Ammonia gas is not collected by downward displacement of water because it is highly soluble in water and gives ammonium hydroxide.
                                        NH₃ + H₂O ----------> NH₄OH

Moist red litmus paper is brought near the mouth of gas jar filled with ammonia to test whether the gas is ammonia or not. Since, ammonia gas is basic in nature, it turns moist red litmus paper to blue.

We all know, ammonia is lighter than air. So, it flows upward in the free state. Therefore, the gas jar is inverted to collect the ammonia gas by downward displacement of air.

We all know, a hard glass test tube is slightly inclined during preparation of ammonia gas, otherwise the steam produced during the reaction exerts pressure, which may crack the test tube. So, the HGTT is slanted to prevent it from cracking.

For commercial purpose, ammonia gas is manufactured by Harber's process. In this process, a mixture of nitrogen and hydrogen (1:3) is combined directly at 500ºc temperature and 200 to600 atm. For this reaction finely powdered iron is taken as a catalyst and molybdenum as a promoter.
                    N₂ + 3H₂ -----------> 2NH₃

Any three chemical properties of ammonia gas are:
        - Ammonia dissolves in water and forms an alkali ie, ammonium hydroxide.
                            NH₃ + H₂O ------> NH₄OH
        - Ammonia is a basic gas. So, it reacts with acid to give salt.
...

Any four physical properties of ammonia gas are:
        - It is colorless, tasteless gas having strong pungent odor.
        - It is lighter than air.
        - It is highly soluble in water.
        - It is basic in nature.
        - It is non-combustible gas.

We can identify ammonia gas by the following ways:
        - Treating moist red litmus paper with ammonia. It turns blue since ammonia is basic in nature.
        - It has a strong pungent odor.
        - When a glass rod dipped in conc. Hcl is brought in contact with ammonia gas, it forms a white fume of NH₄cl. 

In the laboratory, ammonia gas s prepared by heating the mixture of ammonium chloride and calcium hydroxide in the ratio 2:1.
                    2NH₄CL + Ca(OH)₂ ---------> Cacl₂ +2H₂O + 2NH₃