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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
State one relevant observation for given reactions:
Action of concentrated Sulphuric acid on hydrated copper sulfate
Give reason for the following:
When concentrated sulphuric acid is exposed to air, its volume increases and it becomes slightly dilute.
Why is sulphuric acid known as king of chemicals and oil vitriol ?
Choose the current answer from the options given below :
The catalyst used for the oxidation of SO2 to SO3 in contact process is
What would you see, when a crystal of CuSO4.5H2O is placed in concentrated sulphuric acid? Give reason to explain your observation.
Copy and complete the following table.
Column 3 has the names of gases to be prepared using the substance you enter in column 1, along with dilute or concentrated sulphuric acid, as indicated in column 2.
| Column 1 | Column 2 | Column 3 |
| Substance reacted with acid | Dilute or concentrated sulphuric acid | Gas |
| Hydrogen | ||
| Carbon dioxide | ||
| Only chlorine |
Write the equation for the laboratory preparation of :
(i) Sodium sulphate using dilute sulphuric acid.
(ii) Lead sulphate using dilute sulphuric acid.
Write the equation for the laboratory preparation of the following salts, using sulphuric acid.
Lead sulphate from lead nitrate.
In the given equation identify the role played by concentrated sulphuric acid S + 2H2SO4→ 3SO2 + 2H2O
Distinguish between the following pair of compounds using the test given with brackets:
Dilute sulphuric acid and dilute hydrochloric acid (using barium chloride solution)
Give balanced chemical equation to prepare the following salt:
Sodium sulphate using dilute sulphuric acid
