Chemistry
Nitric acid cannot be concentrated beyond 68% by the distillation of a dilute solution of HNO3. Explain why?
Answer
An aqueous solution of nitric acid (68% concentration) forms a constant boiling mixture at 121°C. A constant boiling mixture is one which boils without change in composition.
Hence on boiling further, the mixture evolves out the vapours of both acid and water in the same proportion as in the liquid.
Therefore, dilute HNO3 cannot be concentrated beyond 68% by boiling.
Related Questions
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(b) Metals like iron, aluminium, cobalt and nickel become passive (inert) with concentrated nitric acid.
(c) Alloying of gold is done with silver or copper.
(a) Give balanced equation for the following.
(1) Sodium hydroxide is added to hydrogen chloride.
(2) Sodium aluminate is treated with water.
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P + 5HNO3 ⟶ H3PO4 + 5NO2 + H2O
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Identify the name of the salt on the basis of the following description.
(a) A salt prepared by the action of strong acid on metal.
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