Three different samples of a salt solution give the following test results: One sample gives a white precipitate with ammonia solution. One sample gives a white precipitate with dilute $NaCl$ solution. One sample gives a black precipitate with $H_2S$. Identify the salt.

An aqueous solution containing $FeSO_4$,$Al_2(SO_4)_3$,and chrome alum is treated with $Na_2O_2$ and heated,followed by filtration. The resulting products are:

The colour of $Mg(OH)_2$ precipitate formed when it is precipitated in the presence of magneson reagent is

Which of the following is an incorrect match for the precipitate (ppt) and its color?

$A$ light greenish coloured salt was soluble in water. On passing $H_2S$ into the solution,a black precipitate was obtained which dissolved readily in $HCl$. The metal ion present is:

$A$ salt with a few drops of conc. $HCl$ gives an apple green colour in a flame test. The group precipitate of the salt is dissolved in acetic acid and treated with $K_{2}CrO_{4}$ to give a yellow precipitate. When the sodium carbonate extract of the salt solution is heated with conc. $HNO_{3}$ and ammonium molybdate, it results in a canary yellow precipitate. The cation and anion present in the salt are respectively,