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प्रश्न
Identify the gas evolved and give the chemical test in the following case:
Dilute hydrochloric acid reacts with sodium sulphite.
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उत्तर
Gas Evolved: When dilute hydrochloric acid reacts with sodium sulphite, the gas evolved is sulphur dioxide.
Reaction:
\[\ce{Na2SO3 + 2HCl -> 2NaCl + H2O + SO2 ^}\]
Chemical Test for sulphur dioxide: Pass the gas through an acidified potassium dichromate (K2Cr2O7) solution.
Observation: The solution changes color from orange to green due to the reduction of chromium from Cr6+ to Cr3+.
\[\ce{SO2 + H2O + K2Cr2O7 + H2SO4 -> Cr2(SO4)3 + K2SO4 + H2O}\]
संबंधित प्रश्न
Identify the acid in the following case:
The acid which produces sugar charcoal from sugar.
Give reason for the following:
When solution of sulphur dioxide is exposed to air, it gets converted to sulphuric acid.
Give reason for the following:
When concentrated sulphuric acid is added to blue crystalline copper sulphate, it turns powdery white.
Give reason for the following:
Cotton clothes get burnt with concentrated sulphuric acid.
How are the following conversion brought about? Give equation and condition:
Sucrose to sugar charcoal.
How are the following conversion brought about? Give equation and condition:
Oxalic acid to carbon monoxide.
Name the anion [negative ion] present in the following compound:
Compound D when warmed with dilute H2SO4 gives a gas which turns acidified potassium dichromate solution green.
- Name the catalyst which helps in the conversion of sulphur dioxide to sulphur trioxide in step C.
- In the contact process for the manufacture of sulphuric acid, sulphur trioxide is not converted to sulphuric acid by reacting it with water. Instead a two-step procedure is used. Write the equations for the two steps involved in D.
- What type of substance will liberate sulphur dioxide from sodium sulphite in step E?
- Write the equation for the reaction by which sulphur dioxide is converted to sodium sulphite in step F.
Dilute sulphuric acid will produce a white precipitate when added to a solution of ______.
Identify the salts P and Q from the observation given below:
On performing the flame test salt P produces a lilac coloured flame and its solution gives a white precipitate with silver nitrate solution. Which is soluble in ammonium hydroxide solution.
