Question

The Kjeldahl method of Nitrogen estimation fails for which of the following reaction products

• A.

  

• B.

  

• C.

  

• D.

  

Answer 1

The correct option is C

The correct answer is:(c)

The Explanation for the correct options:

(c)

• Explanation: The by-product of a chemical reaction that is generated in the greatest quantity. The first reaction in Figure 3 will result in a free radical, in which the cyanide group stabilizes.
• The negative charge is carried by $\mathrm{Cl}$, positive charge is carried by ${\mathrm{NH}}_4$.
• Diagram:

The Explanation for the incorrect options:

(a)

• Explanation: In figure 1, ${\mathrm{NO}}_2$ is more electronegative. the negative charge on a more electronegative atom makes it more stable.
• It is most stable. The negative charge is carried by$\mathrm{Cl}$, positive charge is carried by${\mathrm{N}}_2$.
• Diagram:

(b)

• Explanation: The by-product of a chemical reaction that is generated in the highest quantity. In figure 2, the negative charge is carried by${\mathrm{CH}}_2$
• It is less stable. The negative charge is carried by${\mathrm{CH}}_2$, positive charge is carried by${\mathrm{NH}}_2$.
• Diagram:

(d)

• Explanation: They might dissolve if the nitric acid is heated enough. ${\mathrm{N}}_2\mathrm{Cl}$ with enough sulfuric acid added to the water (gas). Heat is involved, not a reaction between the two.
• The negative charge is carried by$\mathrm{Cl}$, positive charge is carried by${\mathrm{N}}_2$.
• Diagram:

The correct options are (c): A free radical produced by the first reaction will be stabilized by the cyanide group.