Which of the following chemicals may be used to identify three unlabelled beakers containing conc. $NaOH$, conc. $H_{2}SO_{4}$ and water?

Which of the following statements is incorrect?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$BaCrO_4 \downarrow + CH_3COOH \text{ (Excess)} \longrightarrow \text{No reaction}$

For the kinetic study of the reaction of iodide ion with $H_{2}O_{2}$ at room temperature, which of the following statements are correct?
$(A)$ Always use freshly prepared starch solution.
$(B)$ Always keep the concentration of sodium thiosulphate solution less than that of $KI$ solution.
$(C)$ Record the time immediately after the appearance of blue colour.
$(D)$ Record the time immediately before the appearance of blue colour.
$(E)$ Always keep the concentration of sodium thiosulphate solution more than that of $KI$ solution.
Choose the correct answer from the options given below:

Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to:

The number of white coloured salts among the following is .................
$A$. $SrSO_4$ $B$. $Mg(NH_4)PO_4$ $C$. $BaCrO_4$ $D$. $Mn(OH)_2$ $E$. $PbSO_4$ $F$. $PbCrO_4$ $G$. $AgBr$ $H$. $PbI_2$ $I$. $CaC_2O_4$ $J$. $[Fe(OH)_2(CH_3COO)]$