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1 - Anhydrous does not contain any free ions.In the absence of free ions no conductivity of electricity could take place.But aqueous solution of HCl is in a completely ionized form .When HCl dissolved in water it dissociates into hydronium ions(H3Oᐩ) and chloride ions (Cl Ⲻ). Which carry electricity.
2 - When the stopper of a bottle full of hydrogen chloride gas is opened it gives white fumes, due to the formation of hydrchloric acid on reacting with atmospheric water vapour .
3 - Solution of hydrogen chloride posses hydronium ions (H3Oᐩ) which help to conduct electricity and produced hydrochloric acid .So blue litmus paper turns into red.While a solution of HCl in toluene neither turns blue litmus paper in red nor conducts electricity because the absence of H3Oᐩ.
4 - If a rod dipped in ammonium hydroxide bring near the the mouth of bottle full of HCl gas dense white fumes of ammonium chloride will be produced.
HCl + NH4OH →NH4Cl + H2O
5 - hydrogen chloride gas does not collected over water because it is highly soluble in water.
6 - Ammonium compounds being highly soluble in water so do not occur as minerals.
7 - Though all ammonium salts give ammonia on heating with alkalies , ammonium nitrate explosive in nature so it is not used in the preparation of ammonia.
8 - Ammonia is basic in nature, so it reacts with sulphuric acid and form ammonium sulphate so it is not used as drying agent . 2NH3 + H2SO4 →(NH 4)2SO4
9 - Liquid ammonia act as a refrigerant in ice plants because evaporation of a liquid needs heat energy .When liquid ammonia vapourizes, it absorbs large quantities of heat with out changing its temperature .
10 - Aqueous solution of ammonia emulsifies or dissolves fats ,so it is used as stain remover.
11 - When ammonia dissolved in water ammonium hydroxide ( aqueous solution of ammonia ) is formed . Thus the pungent smell is due to ammonia gas.
12 - Concentrated Sulphuric acid is hygroscopic in nature . It absorbs moisture from air and it's concentration get change.
13 - All glass apparatus should be used in the preparation of nitric acid because nitric acid vapours attack rubber and cork.
14 - Nitric acid is kept in a reagent bottle because in presence of sunlight or heat it decomposes  and gives yellow solution of NO₂.To avoid the decomposition nitric acid is normally stored in reagent bottle.
15 - A freshly prepared ferrous sulphate solution is used for testing the nitrate radical in the brown ring test , because on exposure to the atmosphere, it is oxidized to ferric sulphate which will not give the brown ring.
16 - Pure nitric acid is colorless but the acid obtained in laboratory is slightly yellow, because the yellow color is due to the dissolution of reddish brown colored nitrogen dioxide gas in the acid.This gas is produced due to yhe thermal decomposition of a portion of nitric acid.
17 - Sulphuric acid is dibasic acid and has two replaceable hydrogen ion . Hence it can forms two types of salt with NaOH.
 NaOH + H₂SO₄ → NaHSO₄ + H₂O
2NaOH  + H₂SO₄ → NaSO₄ + 2H₂O
18 - When concentrated sulphuric acid is added to hydrogen bromide red brown vapors of bromine is produced .2HBr + H₂SO₄ → Br₂ + 2H₂O + SO₂
19 - Conc. Sulphuric acid is a dehydrating agent . It decomposes cellulose present in wood to carbon and turn into black. C₆H⒓O₆ → 6C + 6H₂O 
20 - Oil of Vitriol is sulphuric acid , and when it is reacted with sodium carbonate produced carbon dioxide and water. Which create brisk effervescence.
21 - Ethyne has triple bond so it is highly stressed and has a great deal of energy to release when it is broken. So bonds are broke quickly.
22 - Ethene is more reactive than ethane because ehtene has double bond in between carbon atoms so it is unsaturated presence of pi bond ,and more ready to react to break these pi bond and achieve higher stability.
23 -Hydrocabons have covalent bond in between the carbon atoms which possess a great amount of energy , which is released when these bonds are broken. Hence it is a excellent fuels.
24 - Impurity of arsenic acid must be removed because when it enters the catalytic chamber it poisons the catalyst and efficiency of reaction would be less.
25 - Anhydrous acetic acid means there is no water sometimes called glacial acetic acid because it solidified just below room temperature at 16.7𝆩C . Acetic acid converts into crystal at that temperature.





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