Analytical Chemistry Question 97

Question: Sodium carbonate cannot be used in place of ammonium carbonate for the precipitation of the fifth group radicals because

[AIIMS 1980]

Options:

A) Sodium ions interfere with the detection of fifth group radicals

B) Concentration of carbonate ions is very low

C) Sodium will react with acidic radicals

D) Magnesium will be precipitated

Show Answer

Answer:

Correct Answer: D

Solution:

When $ {{( NH_4 )}_2}CO_3 $ is used then the concentration of $ CO_3^{2-} $ is comparatively low but when $ Na_2CO_3 $ is added then concentration of $ CO_3^{2-} $ increases so $ M{g^{2+}} $ will be precipitated along with other 5th group radicals