When calcium ions $\left({\mathrm{Ca}}^{2+}\right)$ react with ammonium carbonate in the presence of ammonium hydroxide and ammonium chloride, what colour does the resulting product exhibit?

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

What is the chemical formula of the precipitate formed in the potassium hexacyanidoferrate(II) test for calcium ions?

Which complex is formed in the presence of calcium ions when potassium hexacyanidoferrate(II) is added?

What is the appearance of the precipitate formed in the concentrated ammonium oxalate solution test for calcium ions?

Which of the following is the balanced chemical equation for the reaction between calcium ions and concentrated ammonium oxalate solution?

What is the expected chemical equation for the reaction between calcium ions and ammonium carbonate in the presence of ammonium hydroxide?