Revision Notes for ICSE Class 10 Chemistry Chapter 10 - Free PDF Download
FAQs on ICSE Class 10 Chemistry Revision Notes Chapter 10 - Nitric Acid
1. Describe the colour of:
Pure nitric acid.
During the preparation of nitric acid which is obtained in the lab.
Nitric acid during its preparation treated with water or air is blown through it.
Its colour is colourless.
The nitric acid during its lab preparation is pale yellow in colour.
The presence of pale yellow colour disappears and it becomes colourless.
The natural compound is colourless, however, older samples generally tend to accumulate a yellow forged because of decomposition into oxides of nitrogen and water. Most commercially to be had nitric acid has the attention of 68% in water.
When the answer carries extra than 86% HNO3, it's far called fuming nitric acid.
Depending on the quantity of nitrogen dioxide present, fuming nitric acid is similarly characterised as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%.
2. What is aqua regia? How does it dissolve gold?
It is a mixture of three parts of concentrated HCL and one part is of concentrated nitric acid and it is called Aqua Regia. It leads to the supply of nascent chlorine which helps in dissolving gold.
HNO3+3HClNOCl+Cl2+2H2O
Au+3ClAuCl3
Aqua regia is usually accustomed to dissolving gold and platinum. It and alternative similar mixtures are used in analytical procedures for the solution of certain iron ores, phosphate rocks, slags, nickel-chromium alloys, antimony, selenium, and a few of the less-soluble sulphides, equivalent to those of mercury, arsenic, cobalt, and lead.
3. How does the addition of nitric acid to acidified ferrous sulphate act as a test for nitric acid?
Nitric acid oxidises iron (II) sulphate to iron(III) sulphate with the production of nitric oxide gas.
FeSO4+HNO3+H2SO4Fe2[SO4]3+NO+H2O
The nitric oxide which is formed reacts with iron (II) sulphate in order to produce nitroso ferrous sulphate which would look like a brown ring at the surface of the liquid.
FeSO4+NOFe(NO)SO4
The test is used to detect the presence of nitrate ions. This is done by adding ferrous sulphate to the nitric acid solution. Nitrate salts are soluble in water and act as oxidants. This Fe + 3 reacts with sulphate ions to form Fe2[SO4]3 which is a brown solid formed.
4. What are the uses of Nitric acid?
The uses of nitric acid are as follows:
Apply in the manufacturing process of dyes and drugs.
Apply in making explosives such as trinitrotoluene, or TNT, nitroglycerine, and picric acid.
The salts like ammonium nitrate as well as calcium nitrate are basically used as a fertiliser.
Gold and silver were used to get purified with the help of this in their purification process.
Apply in the pickling of stainless steel, etching of metals, and as an oxidizer in rocket fuels.
5. What are the properties of Nitric acid?
The properties are as follows:
Colourless, fuming, and highly corrosive liquid (freezing point −42 °C [−44 °F]
Boiling point-83 °C [181 °F])
It is toxic and can lead to severe burns.
Nitric acid is a very strong acid; it turns bluish-purple in colour.
Nitric acid decomposes to brown nitrogen dioxide when standing. This is why it turns brown over time, even though fresh nitric acid is colourless.
4HNO34NO2+O2+H2O
Nitric acid releases hydrogen gas with metals above hydrogen in the metal activity series.
Mg+2HNO3MH(NO3)2+H2
Mn+2HNO3Mn(NO3)2+H2
