Describe the chemical tests to identify carbon dioxide, ammonia, and hydrogen sulfide.

Question

ScanSolve AI Tutor · Accepted Answer

here are the chemical tests to identify the given gases:

1) Identification of Carbon Dioxide ( $\text{CO}_2$ )

Pass the gas through limewater (calcium hydroxide solution).
Observe the change.
Carbon dioxide turns limewater milky due to the formation of insoluble calcium carbonate.
$\text{Ca(OH)}_2(\text{aq}) + \text{CO}_2(\text{g}) \rightarrow \text{CaCO}_3(\text{s}) + \text{H}_2\text{O}(\text{l})$
2) Identification of Ammonia ( $\text{NH}_3$ )
Bring a glass rod dipped in concentrated hydrochloric acid ( $\text{HCl}$ ) near the gas.
Observe the change.
Ammonia reacts with hydrogen chloride gas (from the concentrated $\text{HCl}$ ) to form dense white fumes of ammonium chloride.
$\text{NH}_3(\text{g}) + \text{HCl}(\text{g}) \rightarrow \text{NH}_4\text{Cl}(\text{s})$
3) Identification of Hydrogen Sulfide ( $\text{H}_2\text{S}$ )
Pass the gas through lead(II) acetate paper (or solution).
Observe the change.
Hydrogen sulfide turns lead(II) acetate paper black due to the formation of lead(II) sulfide.
$\text{Pb(CH}_3\text{COO)}_2(\text{aq}) + \text{H}_2\text{S}(\text{g}) \rightarrow \text{PbS}(\text{s}) + 2\text{CH}_3\text{COOH}(\text{aq})$

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