Question

In the qualitative inorganic analysis of basic radicals, hydrochloric acid is preferred to nitric acid for preparing a solution of a given substance. This is because:
A) Nitrates are per decomposed to sulfides
B) Nitric acid contain nitrogen
C) Hydrochloric acid is not an oxidizing agent
D) Chlorides are easily converted to sulfides

Answer 1

Basic radicals are the metal cations. The use of $\text{HCl}$ is preferred over $\text{HN}{{\text{O}}_{\text{3}}}$ because nitric acid is a strong oxidizing agent that oxidizes the metal ions such that some of the reactions may not take place in the solution. The $\text{HCl}$form the chlorides of the metal which are soluble in the aqueous medium.

Complete answer:
Basic radicals are the ion which is obtained from the base. These are positively charged species. This is cation produced in aqueous solution from the inorganic salts. Some examples of basic radical or cations are$\text{N}{{\text{a}}^{\text{+}}}$,$\text{P}{{\text{b}}^{\text{2+}}}$, $\text{Z}{{\text{n}}^{\text{2+}}}$ etc.
Basic radials are classified into six groups. Each group has its reagent. The radicals react with the salt to form an aqueous solution of the metal ion. Generally a dilute $\text{HCl}$ is used to prepare the solutions of given metal salts.
$\text{HCl}$ Is a strong acid and easily ionizes into the${{\text{H}}^{\text{+}}}$ and $\text{C}{{\text{l}}^{\text{-}}}$ ions.it is widely used in the qualitative analysis of group II metal ions.
The basic radicals readily dissociate $\text{HCl}$ into its corresponding ions. These radicals or cations from the chlorides of it.Group metals
Group I cations $\text{P}{{\text{b}}^{\text{2+}}}$ readily precipitated with the $\text{HCl}$ as chloride.
Lead is precipitated as the lead chloride $\text{PbC}{{\text{l}}_{\text{2}}}$ which confirms the presence of group I elements
$\begin{aligned} & \text{P}{{\text{b}}^{\text{2+}}}+2\text{C}{{\text{l}}^{\text{-}}}\to \text{PbC}{{\text{l}}_{\text{2}}}(\downarrow ) \\\ & \text{A}{{\text{g}}^{\text{+}}}\text{+C}{{\text{l}}^{\text{-}}}\to \text{AgCl(}\downarrow \text{)} \\\ \end{aligned}$
Most of the metal ions are soluble in $\text{HCl}$ reagent except the group I elements. $\text{HCl}$ is used for the analysis of group II cations. The group II metals have low solubility product and thus easily precipitates on the exposure to${{\text{H}}_{\text{2}}}\text{S}$.$\text{HCl}$ do not oxidize the metal ions and are used as the group reagent.
This $\text{HN}{{\text{O}}_{\text{3}}}$ is not advisable as a group reagent because it is a strong oxidizing agent. It oxidizes the metal ions in the solution itself undergoes the reduction to form oxides of nitrogen.
Nitrogen adds the electron to the metal and gets reduced.
For example, when the $\text{Pb}$ metal reacts with the metal the redox reaction takes place. The lead metal forms the $\text{PbO}$ which acts as a covering on the remaining metal in the solution and thus makes the metal unable or inaccessible for acid for further treatment. Therefore, no expected reaction takes place.
While such a type of reaction does not take place when $\text{HCl}$ is used as the solvent. Because $\text{HCl}$ is not a strong oxidizing agent.
Thus, in the qualitative inorganic analysis of basic radicals, hydrochloric acid is preferred to nitric acid for preparing a solution of a given substance.

Hence, (C) is the correct option.

Note:
$\text{HCl}$ is not an oxidizing agent but can be oxidized by to liberate the chlorine gas. Remember that nitric acid is a bulky group that also hinders the reaction with the metal.