Question

Select the correct statement regarding the test of 5th group cations.

• A. Cations are tested with their respective colours of precipitate.
• B. They are tested with their solubility test in different solutions.
• C. They are tested using borax bead.
• D. Since most of the precipitate formed in 5th group is white coloured so we test those precipitate by flame test.

Answer 1

The correct option is D Since most of the precipitate formed in 5th group is white coloured so we test those precipitate by flame test.

$C{a}^{+2},B{a}^{+2}$ and $S{r}^{+2}$ are ions of 5th group, so when they react with ${\left(N{H}_4\right)}_{2}C{O}_3.$ they for corresponding $carbonates$ of the ions, which are white in color.

Thus, now they can be distinguished by flame coloration.

$Ba$ gives apple green flame,

$Ca$ gives brick red,

$Sr$ gives crimson red flame.