JEE Main2013Chemistrys Block ElementsActual
Sodium Carbonate cannot be used in place of ( NH ₄ )₂ CO ₃ for the identification of Ca ²⁺, Ba ²⁺ and Sr ²⁺ ions (in group V ) during mixture analysis because :
Options
- AMg ²⁺ ions will also be precipitated.
- BConcentration of CO ₃ ²⁻ ions is very low.
- CSodium ions will react with acid radicals.
- DNa ⁺ ions will interfere with the detection of Ca ²⁺, Ba ²⁺, Sr ²⁺ ions.
Correct answer
A. Mg ²⁺ ions will also be precipitated.
Step-by-step solution
If Na ₂ CO ₃ is used in place of ( NH ₄ )₂ CO ₃ . It will precipitate group V radicals as well as magnesium radicals. The reason for this is the high ionization of Na ₂ CO ₃ in water into Na ⁺ and CO ₃⁻⁻ . Now the higher concentration of CO ₃⁻⁻ is available which exceeds the solubility product of group V radicals as well as that of magnesium radicals.