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(A) In the analysis of group $V$ cations,$(NH_4)_2CO_3$ is used as a group reagent in the presence of $NH_4Cl$ and $NH_4OH$.$NH_4Cl$ suppresses the io

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$Mg^{2+}$ ions will also be precipitated

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(A) In the analysis of group $V$ cations,$(NH_4)_2CO_3$ is used as a group reagent in the presence of $NH_4Cl$ and $NH_4OH$.$NH_4Cl$ suppresses the ionization of $(NH_4)_2CO_3$ due to the common ion effect,keeping the concentration of $CO_3^{2-}$ low enough to exceed only the solubility product $(K_{sp})$ of $Ca^{2+}$,$Ba^{2+}$,and $Sr^{2+}$ carbonates.If $Na_2CO_3$ is used instead,it is a strong electrolyte and dissociates completely to provide a high concentration of $CO_3^{2-}$ ions.This high concentration of $CO_3^{2-}$ exceeds the $K_{sp}$ of $MgCO_3$ as well,causing $Mg^{2+}$ ions to precipitate along with the group $V$ cations.

Cations	Group reaction
$P \rightarrow Pb^{2+}, Cu^{2+}$	$(i)$ $H_2S$ gas in presence of dilute $HCl$
$Q \rightarrow Al^{3+}, Fe^{3+}$	$(ii)$ $(NH_4)_2CO_3$ in presence of $NH_4OH$
$R \rightarrow Co^{2+}, Ni^{2+}$	$(iii)$ $NH_4OH$ in presence of $NH_4Cl$
$S \rightarrow Ba^{2+}, Ca^{2+}$	$(iv)$ $H_2S$ in presence of $NH_4OH$

Sodium Carbonate cannot be used in place of $(NH_4)_2CO_3$ for the identification of $Ca^{2+}$,$Ba^{2+}$,and $Sr^{2+}$ ions (in group $V$) during mixture analysis because

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$A$ $0.3 \, M$ $HCl$ solution contains the following ions: $Hg^{2+}, Cd^{2+}, Sr^{2+}, Fe^{2+}, Cu^{2+}$. The addition of $H_2S$ to the above solution will precipitate which of the following?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Fe(OH)_3 \downarrow + NaOH(\text{excess}) \longrightarrow \text{No reaction}$

$A$ mixture of $NaCl$ and $K_{2}Cr_{2}O_{7}$ is heated with conc. $H_{2}SO_{4}$,deep red vapours are formed. Which of the following statements is false?

Which of the following pairs cannot be distinguished by passing $H_2S$ gas?

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