When we add dilute sulphuric acid to salt, brisk effervescence is observed then the possible anion is carbonate.

Distinguish between the following pair of compounds using a reagent as a chemical test:

• Magnesium chloride and magnesium nitrate solution.

Then A may have:

The _____ gas is released when hydrochloric acid is added to the test compound. It indicates the presence of carbonate ions.

To an acid solution of an anion a few drops of KMnO₄ solution are added. Which of the following, if present will not decolourise the KMnO₄ solution

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 $100\}$

${\mathrm{CaCO}}_3\stackrel{\mathrm{\Delta }}{⟶}\mathrm{A}+\mathrm{B} \left(\mathrm{g}\right)$

$\mathrm{A}+{\mathrm{H}}_2\mathrm{O}⟶\mathrm{C}$

$\mathrm{C}+\mathrm{B}⟶\underset{\left(\mathrm{white} \mathrm{precipitate}\right)}{\mathrm{D}}+{\mathrm{H}}_2\mathrm{O}$

$\mathrm{D}+\mathrm{B} \left(\mathrm{g}\right)\to \underset{\left(\mathrm{water} \mathrm{soluble}\right)}{\mathrm{E}}\underset{{\mathrm{BaCl}}_2}{\stackrel{\mathrm{Boil}}{\to }}\underset{(\mathrm{white} \mathrm{precipitate})}{\mathrm{F}}$

Note: Question details are changed from that of the book.

Select the correct option(s) for the white precipitate shown in the above reactions.