Which of the following statement(s) is/are correct regarding group V cations?

S r^{2 +}

ions have a crimson coloured flame.

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The Group V cations are precipitated as their carbonates which dissolve in acetic acid due to the formation of corresponding acetates.

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All of the above.

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B a^{2 +}

ions have a grassy green coloured flame.

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Solution

The correct option is C All of the above.
Take original solution and add small amount of solid $N H_{4} C l$ and an excess of $N H_{4} O H$ solution followed by solid ammonium carbonate $(N H_{4})_{2} C O_{3}$

White precipitate indicates the presence of group V cations
The Group–V cations are precipitated as their carbonates which dissolve in acetic acid due to the formation of corresponding acetates.

Test for $B a^{2 +}$ Ions:
Potassium chromate $(K_{2} C r O_{4})$ solution gives a yellow precipitate of barium chromate when the solution of fifth group precipitate in acetic acid is treated with it.
$B a C O_{3} + 2 C H_{3} C O O H \to (C H_{3} C O O)_{2} B a + H_{2} O + C O_{2}$

$(C H_{3} C O O)_{2} B a + K_{2} C r O_{4} \to B a C r O_{4} Barium chromate (yellow precipitate) + 2 C H_{3} C O O K$
A grassy green colour of the flame confirms the presence of $B a^{2 +}$ ions.

Test for $S r^{2 +}$ Ions
Ammonium sulphate $(N H_{4})_{2} S O_{4}$ solution gives a white precipitate of Strontium sulphate when the solution of fifth group precipitate in acetic acid is treated with it.
$S r C O_{3} + 2 C H_{3} C O O H \to (C H_{3} C O O)_{2} S r + H_{2} O + C O_{2}$

$(C H_{3} C O O)_{2} S r + (N H_{4})_{2} S O_{4} \to S r S O_{4} Strontium sulphate (white precipitate) + 2 C H_{3} C O O N H_{4}$
A crimson red flame confirms the presence of $S r^{2 +}$ ions.

Test for $C a^{2 +}$ Ions:
Solution of the fifth group precipitate in acetic acid gives a white precipitate with ammonium oxalate solution
$C a C O_{3} + 2 C H_{3} C O O H \to (C H_{3} C O O)_{2} C a + H_{2} O + C O_{2}$

$(C H_{3} C O O)_{2} c a + (N H_{4})_{2} C_{2} O_{4} Ammonium oxalate \to (C O O)_{2} C a Calcium oxalate (white precipitate) + 2 C H_{3} C O O N H_{4}$

Calcium imparts brick red colour to the flame which looks greenish-yellow through blue glass

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