What are the observations and inferences for adding Pb(NO₃)₂[aq], acidified KMnO₄, and HNO₃ to unknown substances in a qualitative analysis test?

Here are the observations and inferences for the tests described in the image. Since the initial substance is not specified, I will provide common expected results for qualitative analysis.

iii) To the 3rd portion, add 2 drops of Pb(NO₃)₂[aq]

• OBSERVATIONS: A white precipitate is formed.
• INFERENCES: Presence of $\text{Cl}^-$, $\text{SO}_4^{2-}$, or $\text{CO}_3^{2-}$ ions.

iv) To the 4th portion, add acidified KMnO₄

• OBSERVATIONS: The purple color of acidified $\text{KMnO}_4$ decolorizes.
• INFERENCES: Presence of a reducing agent (e.g., $\text{Fe}^{2+}$, $\text{SO}_3^{2-}$, $\text{NO}_2^{-}$).

B (i) Put the residue in a test tube and add about $2\text{cm}^3$ of $\text{HNO}_3$.

• OBSERVATIONS: Effervescence (a colorless, odorless gas is evolved).
• INFERENCES: Presence of a carbonate ($\text{CO}_3^{2-}$) or sulfite ($\text{SO}_3^{2-}$).