Qualitative Analysis Questions

Match List I with List IIList I (Ion)A. $C{o}^{2+}$ B. $M{g}^{2+}$ C. $P{b}^{2+}$ D. $A{l}^{3+}$ List II (Group Number in Cation Analysis)I. Group-III. Group-IIIIII. Group-IVIV. Group-VIChoose the correct answer from the options given below:

H2S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because :

The Lassaigne's extract is boiled with conc. ${\text{HNO}}_3$ while testing for halogens. By doing so it:

Assertion : Addition of ${\text{NH}}_4\text{OH}$ to an aqueous solution of ${\text{BaCl}}_2$ in the presence of ${\text{NH}}_4\text{Cl}$ (excess) precipitates $\text{Ba}(\text{OH}{)}_2$.Reason : $\text{Ba}(\text{OH}{)}_2$ is insoluble in water.

Red precipitate is obtained when ethanol solution of dimethylglyoxime (DMG) is added to ammoniacal $\text{Ni(II)}$. Which of the following statements is NOT true?

${\text{CH}}_3\text{CHO}$ and ${\text{C}}_6{\text{H}}_5{\text{CH}}_2\text{CHO}$ can be distinguished chemically by: