Prabin Kalikote

The precautions needed during the laboratorypreparation of CO₂ are:
-The apartus should be made air tight.
-The Lower end of deliverytube should not touch thesolution within the woulfe's bottle.
-The lower end of thistle funnel should be dipped inthe solution.
-Carbon dioxide is collected in the gas jar by theupward displacementof air.

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 turnsmilky white due to the formation of insoluble CaCo₃.When CO₂ is passed in lime water for long time, themilky color disappearsdue to the formation of solubleCa(HCO₃)₂.
-CO₂ turns blue litmus paper to red because it isacidicin nature.

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

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

Ammonia gas prepared by heating a mixture ofNH₄CL and CA(OH)₂.
2NH₄Cl + Ca(OH)₂---------> CaCl₂ + 2H₂O + 2NH₃

The uses of ammoniagas are:
-It is used to manufacture chemical fertilizers.
-Liquidammoniais 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 dioxidereact together at about 1500Cunder certain pressure(30atom).
2NH₃ + CO₂----------> NH₂ - CO - NH₂ + H₂O