Which reagent can be used to identify nickel ion $(Ni^{2+})$?

Which of the following reagents is commonly used to detect the presence of sulfide ions?

Which reagent is used to distinguish between silver and lead salts?

The solution of $BiCl_{3}$ in dil. $HCl$ when diluted with water,forms a white precipitate which is:

Given below are certain cations. Using inorganic qualitative analysis,arrange them in increasing group number from $0$ to $VI$.
$A. Al^{3+}$ $B. Cu^{2+}$
$C. Ba^{2+}$ $D. Co^{2+}$
$E. Mg^{2+}$
Choose the correct answer from the options given below:

The compound that is white in color is