Advertisements
Advertisements
Question
What is Nessler’s reagent?
Advertisements
Solution
- Nessler's reagent is a solution of mercury(II) iodide (HgI2) in potassium iodide (KI) and potassium hydroxide (KOH) named after the German chemist Julius Nessler.
- Nessler’s reagent is an alkaline solution of K2 HgI4.
- It is used in testing for ammonia, with which it forms a brown colouration or precipitate.
\[\ce{NH3 + 2[HgI4]^2- + 4OH^- → HgO.Hg(NH2) + 7I^- + 3H2O}\]
-
Low ammonia: Yellow coloration
-
High ammonia: Reddish-brown precipitate
This color change confirms the presence of ammonia.
APPEARS IN
RELATED QUESTIONS
Describe the laboratory method of preparation of ammonia
What is the action of Excess of air on ammonia ?
What is the action of the following reagents on ammonia :
Nessler's reagent
Mention the conditions required to maximise the yield of ammonia.
How does ammonia react with a solution of Cu2+?
How is ammonia manufactured industrially?
What is the action of Na Metal on ammonia?
What is the action of the following reagents on ammonia :
Sodium metal
In laboratory ammonia is prepared by heating:
Which compound is used in the preparation of caprolactam?
Which compound is used as the cooling liquid in refrigerators?
Ammonia act as a Lewis base because nitrogen has ____________.
Ammonia on reaction with hypochlorite anion can form:
The shape of ammonia molecule is ____________.
Liquid ammonia bottles are opened after cooling them in ice for some time. It is because liquid NH3 ____________.
Ammonia is generally manufactured for fertilizers by the reaction:
In qualitative analysis when \[\ce{H2S}\] is passed through an aqueous solution of salt acidified with dil. \[\ce{HCl}\], a black precipitate is obtained. On boiling the precipitate with dil. \[\ce{HNO3}\], it forms a solution of blue colour. Addition of excess of aqueous solution of ammonia to this solution gives ______.
A brown ring is formed in the ring test for \[\ce{NO3^{-}}\] ion. It is due to the formation of ______.
In the preparation of HNO3, we get NO gas by catalytic oxidation of ammonia. The moles of NO produced by the oxidation of two moles of NH3 will be ______.
What happens when reactions:
Benzylchloride is treated with ammonia followed by the reaction with Chloromethane.
