Regarding the group VI cation Mg^2+, which statements are correct?

With Na2HPO4 in ammoniacal medium it gives white Mg(NH4)PO4.

It is not precipitated by (NH4)2CO3 in the presence of NH4Cl and NH4OH.

With magneson reagent in alkaline medium it gives a blue lake (adsorbed on Mg(OH)2).

With Na2HPO4 in ammoniacal medium it gives white Mg(NH4)PO4.

It is precipitated as Mg(OH)2 by NH4OH in the presence of excess NH4Cl in group III.

It is not precipitated by (NH4)2CO3 in the presence of NH4Cl and NH4OH.

With magneson reagent in alkaline medium it gives a blue lake (adsorbed on Mg(OH)2).

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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3qc039

Regarding the group VI cation $Mg X^{2 +}$ , which statements are correct?

AWith $Na X_{2} HPO X_{4}$ in ammoniacal medium it gives white $Mg (NH X_{4}) PO X_{4}$ .
BIt is precipitated as $Mg (OH) X_{2}$ by $NH X_{4} OH$ in the presence of excess $NH X_{4} Cl$ in group III.
CIt is not precipitated by $(NH X_{4}) X_{2} CO X_{3}$ in the presence of $NH X_{4} Cl$ and $NH X_{4} OH$ .
DWith magneson reagent in alkaline medium it gives a blue lake (adsorbed on $Mg (OH) X_{2}$ ).

Answer: A, C, D

In the buffered ammoniacal medium

[OH X^{-}]

is too low for

Mg (OH) X_{2}

, and magnesium is carried through group V to group VI. Group VI tests are the phosphate precipitate and the blue magneson lake. Statement 4 is false for the reason just given.

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Regarding the group VI cation MgX2+, which statements are correct?

Answer: A, C, D

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Regarding the group VI cation $Mg X^{2 +}$ , which statements are correct?