Anuska Bashyal

Write the action of aquaregia on gold.

Aqua regia is a mixture of nitric acid (HNO₃) and hydrochloric acid (HCl), in a molar ratio of 1:3.

Aqua regia is capable of dissolving gold.

Write down the manufacture of HNO3 by catalytic oxidation of ammonia.

Write physical and chemical principles of Ammonia. Why NH3 can't be dried by passing overconc. H2SO4?

Ammonia cannot be dried by passing over conc.H2SO4 becauseammonia gas reacts chemically with conc.H2SO4to form(NH) SO ammonium sulphate.

Conc.H2SO4is a very good oxidizing agent.

Describe Haber's process for the manufacture of ammonia. Why is NH3 not dried over conc.H2SO4 and anhydrous CaCl2? What is the action when ammonia is passed to mercurousnitrate paper and FeSO4 solu...

Conc.H2SO4and anhydrousCaCl₂are not used to dry ammonia because they form chemical compounds with it.

- conc.H2SO4 and NH3 form(NH) SO

- While anhydrous CaCl₂absorbs water, it undergoes hydrolysis to give hydrochloric acid.

Since ammonia is basic, it is neutralised by HCl to give salt,NH3 + HCl NH4Cl.

Ammonia passed through the paperturns mercurous nitrate paper into black. It is due to the formation of mercuric amidonitrate and mercury.

Again,

when ammonia is passed through FeSO4 solution,a dirty...

What happens when the precipitate obtained by the addition of AgNO3 solution on sodiumchloride is treated with ammonia solution?

When the White ppt. obtained by treating NaCl solution with Ag NO3 solution is again treated with ammonia solution, it forms a water soluble salt, that will make the solution clear.

NaCl (aqueous) Na⁺+ Cl ^-

What happens when freshly prepared ferrous sulphate is added to the mixture of conc. nitricacid and conc. sulphuric acid?

When FeSO4 is added to the mixture of HNO3 and conc. H2SO4, it give brown ring ofNitrosylferrous Sulphate (FeSO4.NO) which forms on the point of contact of the two reagents.

It is used to give the test of nitric acid known as brown ring test.

Describe the principle involved in the manufacture of ammonia by Haber's process. Whathappens when ammonia gas is passed through heated CuO?

Haber Process is used to obtain ammonia by reacting nitrogen from the air with hydrogen (derived mainly from methane).

Principle:

Hydrogen doesn’t react with Nitrogen at ordinary temperature . But when the mixture of pure Nitrogen and Hydrogen in ratio 1:3 by volume is heat at 450C under a pressure 200-900 atm in presence of Fe and Mo as catalyst Ammonia gas is obtained.

N2+ 3H2———–> 2NH3+ 22.4Kcal