On passing a gas, ‘X’, through Nessler’s reagent, a brown precipitate is obtained. The gas ‘X’ is
- $\text{H}_2\text{S}$
- $\text{CO}_2$
- $\text{NH}_3$
- $\text{Cl}_2$
The Correct Option is C
Approach Solution - 1
To answer the question of which gas 'X' produces a brown precipitate with Nessler's reagent, let's examine the options and the reaction involved.
Nessler's Reagent Reaction:
Nessler's reagent is a chemical solution used to detect the presence of ammonia (\(\text{NH}_3\)) in a sample. When ammonia gas is passed through Nessler's reagent, it reacts to form a brown precipitate of mercuric amido-iodide, which indicates the presence of ammonia.
The relevant reaction is:
\(\text{NH}_3 + 2\text{K}_2\text{HgI}_4 + 3\text{KOH} \rightarrow \text{HgO}\cdot\text{Hg(NH}_2\text{I}) + 7\text{KI} + 2\text{H}_2\text{O}\)
Option Analysis:
- \(\text{H}_2\text{S}\): When hydrogen sulfide is passed through Nessler's reagent, it does not form a brown precipitate. Instead, it reacts with metal ions to form black metal sulfides.
- \(\text{CO}_2\): Carbon dioxide does not react with Nessler's reagent to form any precipitate.
- \(\text{NH}_3\): This is the gas that reacts with Nessler's reagent to produce a brown precipitate, indicating the presence of ammonia.
- \(\text{Cl}_2\): Chlorine does not react with Nessler's reagent to produce a brown precipitate.
Therefore, the correct answer is the gas that reacts with Nessler's reagent to form a brown precipitate, which is \(\text{NH}_3\).
Conclusion:
Gas 'X' that forms a brown precipitate with Nessler's reagent is \(\text{NH}_3\), or ammonia.
Approach Solution -2
Nessler’s Reagent Reaction:
\(2K_2HgI_4 + NH_3 + 3KOH \rightarrow Hg_2(NH_3)_2I_2 + 7KI + 2H_2O\)
In the reaction above, the formation of a brown precipitate is characteristic of ammonia gas (\( NH_3 \)).
The Correct Answer is: \( NH_3 \)
Top JEE Main Chemistry Questions
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)- At equilibrium the concentrations of and in a sealed vessel at . What will be for the reaction
- Find out the major products from the following reactions
Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
- The correct order of atomic radii is:
Top JEE Main Qualitative Analysis Questions
- Given below are two statements:
Statement-I: The gas liberated on warming a salt with dil H2SO4, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion.
Statement-II: In statement-I the colour of paper turns black because of formation of lead sulphite. In the light of the above statements, choose the most appropriate answer from the options given below: - The Lassaigne’s extract is boiled with dil HNO\(_3\) before testing for halogens because
- In chromyl chloride test for confirmation of Cl-, a yellow solution is obtained. Acidification of the solution and addition of amyl alcohol and 10% H2O2 turns organic layer blue indicating formation of chromium pentoxide. The oxidation state of chromium in that is
- A reagent which gives brilliant red precipitate with Nickel ions in basic medium is
- $\text{The oxidation number of iron in the compound formed during brown ring test for NO}_3^-\text{ ion is \_\_\_\_\_\_.}$
Top JEE Main Questions
- Two masses $m$ and $\frac{m}{2}$ are connected at the two ends of a massless rigid rod of length $l$. The rod is suspended by a thin wire of torsional constant $k$ at the centre of mass of the rod-mass system(see figure). Because of torsional constant $k$, the restoring torque is $\tau =k\theta$ for angular displacement $\theta$. If the rod is rota ted by $\theta_0$ and released, the tension in it when it passes through its mean position will be:
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)- The value of is
- The number of terms of an is even. The sum of the odd terms is and of the even terms is . The last term exceeds the first by . Then the number of terms in the series is ______.
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,