ICSE CHEMISTRY CLASS 10 - Give reasons - Nitric acid

ICSE CHEMISTRY CLASS 10 - Give reasons - Nitric acid

1.     Pure Nitric acid takes yellow brown colour when exposed to the light.

Ans: Nitric acid decomposes to give Nitrogen dioxide which remains dissolved in Nitric acid which imparts the yellow colour to the acid.

2.     Only all glass apparatus should be used in the laboratory preparation of Nitric acid.

Ans: Highly corrosive Nitric acid vapours attack the rubber or cork but not glass.

3.     Iron is rendered passive with fuming Nitric acid.       

Ans: Nitric acid oxidizes Iron which results in the formation of a layer which stops the further reaction.       

4.     Nitric acid prepared in lab is in yellow colour.

Ans: Nitrogen dioxide remains dissolved in Nitric acid.

5.     Dil. Nitric acid does not give Hydrogen gas with active metals.

Ans: Dilute nitric acid being an oxidizing agent oxidizes Hydrogen to Water.

6.     Higher ratio of air is used in Ostwald’s process.

Ans: Oxygen is required in the all the three steps of the process.

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