Question

Find the number of ions which are identified by dil HCl from the following:
I.$C{O_3}^{2 - }$
II.$S{O_3}^{2 - }$
III.$S{O_4}^{2 - }$

Answer 1

There are two types of ions present in a solution namely the cation and the anion. The cations are positively charged and the anions are negatively charged, the cations undergo reduction process and the anions undergo oxidation since they are electron deficient and electron rich respectively.

Complete step by step answer:
The branch of chemistry which helps to identify the instruments and methods used to separate, identify, and quantify matter is known as Analytical Chemistry.
A clear visual effect is needed to establish and confirm the presence of a compound in an unknown mixture; the reaction conditions should be very precise and the reaction should be carried out in the isolated laboratory conditions with full precautions of utilizing the clean apparatus for the same purpose. The beast results are obtained from the reactions in which colour change or the formation of a coloured precipitate is observed since it is clearly visible with the naked eye as well while the formation of colourless precipitate is bit difficult to detect. Formation of gas which can again be tested is a good option as well. But such things require proper procedure to be followed with full safety measures.

The $SO_4^{2-}$ ions can be easily detected by the dil. HCl solution, in order to detect the presence of the $SO_4^{2-}$ ion in a sample, adds 5-10 drops of the dil. HCl solution and few drops of the Barium chloride or Barium nitrate solution as well. A white precipitate of BaSO4 will be obtained, this above reaction can be shown as follows: $B{a^{2 + }}(aq) + S{O_4}^{2 - }(aq) \to BaS{O_4}^{2 - }(s)$

Note: Sometimes the masking of ions is also done during the identification of the ions. The activity of some ions is hindered in order to identify the other ion in the solution mixture; this is usually carried out for the ions which have different or variable oxidation states.