Question

Which amongst the following chemicals is used in preliminary tests for anions?

• A. $NaOH$
• B. $H_{2}S{O}_4$
• C. $NaHC{O}_3$
• D. $C{H}_{3}COOH$

Answer 1

The correct option is B $H_{2}S{O}_4$

Anions are negatively charged. A strong acid like $H_{2}S{O}_4$ provides $H^{+}$ cations which can easily react with almost all anions to release various gases. These released gases can be observed as effervescence.

Although most acids can provide $H^{+}$ ions, weak acids like $C{H}_{3}COOH$ cannot be used for analysis. This is because the number of $H^{+}$ ions provided by weak acids will be lesser as compared to strong ones like $H_{2}S{O}_4$ and $HCl$.