Which of the following radicals does not liberate gas with ($Zn$ + dil. $HCl$) on warming?

When salt $BA$ is treated with concentrated $H_2SO_4$, a reddish-brown gas is liberated. The aqueous solution of $BA$ gives a pale yellow precipitate with $AgNO_3$ solution. Which of the following anions $(A^-)$ is present in the salt $BA$?

Aqueous solution of a salt $(A)$ forms a dense white precipitate with $BaCl_{2}$ solution. The precipitate dissolves in dilute $HCl$ to produce a gas $(B)$ which decolourises acidified $KMnO_{4}$ solution. $A$ and $B$ respectively are

When $Cl_2$ water is added to a salt solution containing chloroform,the chloroform layer turns violet. The salt contains:

When $BaCl_2$ is added to a clear solution of a compound $(X)$,a heavy white precipitate is formed which does not dissolve in $dil. HCl$. What is the compound $(X)$?

Which of the following silver precipitates dissolves in $dil. \, HNO_3$ to produce a clear solution?