JEE Main 2015 — Chemistry Inorganic Chemistry

$$\begin{matrix} {\text{FeCl}}_{3} & + & 3 {\text{SCN}}_{( \text{aq} )}^{-} & \rightleftharpoons & \text{Fe} { ( \text{SCN} ) }_{3} & + & 3 {\text{Cl}}^{-} \\ & & & & \text{Blood red} & & \end{matrix}$$FeCl3​​+​3SCN(aq)−​​⇌​Fe(SCN)3​Blood red​+​3Cl−​

$$\begin{matrix} 4 {\text{FeCl}}_{3} & + & 3 {\text{K}}_{4} [ \text{Fe} { ( \text{CN} ) }_{6} ] & \rightarrow & 1 2 \text{KCl} & + & {\text{Fe}}_{4} [ \text{Fe} { ( \text{CN} ) }_{6} ] \\ & & & & & & \text{Prussian blue} \end{matrix}$$4FeCl3​​+​3K4​[Fe(CN)6​]​→​12KCl​+​Fe4​[Fe(CN)6​]Prussian blue​

$$2 {\text{FeCl}}_{3} + 3 {\text{H}}_{2} {\text{SO}}_{4} \rightarrow {\text{Fe}}_{2} { ( {\text{SO}}_{4} ) }_{3} + 6 \text{HCl}$$2FeCl3​+3H2​SO4​→Fe2​(SO4​)3​+6HCl

$${\text{K}}_{2} {\text{Cr}}_{2} {\text{O}}_{7} + 2 {\text{H}}_{2} {\text{SO}}_{4} \rightarrow 2 {\text{KHSO}}_{4} + 2 {\text{CrO}}_{3} + {\text{H}}_{2} \text{O}$$K2​Cr2​O7​+2H2​SO4​→2KHSO4​+2CrO3​+H2​O

$$\begin{matrix} {\text{CrO}}_{3} & + & 2 \text{HCl} & \rightarrow & {\text{CrO}}_{2} {\text{Cl}}_{2} & + & {\text{H}}_{2} \text{O} \\ & & & & \text{Chromyl} & & \\ & & & & \text{chloride} & & \end{matrix}$$CrO3​​+​2HCl​→​CrO2​Cl2​Chromylchloride​+​H2​O​

$${ \text{CrO} }_{\text{2}} { \text{Cl} }_{\text{2}} \text{+4NaOH}\rightarrow \underset{ \text{Yellow} }{ { \text{Na} }_{\text{2}} { \text{CrO} }_{\text{4}} } { \text{+2NaCl+2H} }_{\text{2}} \text{O}$$CrO2​Cl2​+4NaOH→YellowNa2​CrO4​​+2NaCl+2H2​O

$$\begin{matrix} {\text{Na}}_{2} {\text{CrO}}_{4} & + & \text{Pb} { ( {\text{CH}}_{3} \text{COO} ) }_{2} & \rightarrow & {\text{PbCrO}}_{4} & + & 2 {\text{CH}}_{3} \text{COONa} \\ & & & & \text{Yellow ppt.} & & \end{matrix}$$Na2​CrO4​​+​Pb(CH3​COO)2​​→​PbCrO4​Yellow ppt.​+​2CH3​COONa​