The spectator ions in the reaction between aqueous perchloric acid and aqueous barium hydroxide are: OH- and ClO4- H+, OH-, ClO4- and Ba+2 H+ and OH- H+ and Ba+2 ClO4- and Ba+2
The Correct Answer and Explanation is:
The correct answer is H+ and Ba+2.
Explanation:
In a neutralization reaction, such as the one between aqueous perchloric acid (HClO4) and aqueous barium hydroxide (Ba(OH)2), the H+ ions from the acid and the OH- ions from the base combine to form water (H2O). The other ions in the solution, which do not participate in the reaction, are called spectator ions.
- Perchloric acid (HClO4) dissociates into H+ and ClO4- ions in aqueous solution.
- The reaction: HClO4→H++ClO4−HClO_4 \rightarrow H^+ + ClO_4^-HClO4→H++ClO4−
- Barium hydroxide (Ba(OH)2) dissociates into Ba+2 and OH- ions.
- The reaction: Ba(OH)2→Ba2++2OH−Ba(OH)_2 \rightarrow Ba^{2+} + 2OH^-Ba(OH)2→Ba2++2OH−
When the two solutions mix, the H+ ions from the acid and the OH- ions from the base react to form water:H++OH−→H2OH^+ + OH^- \rightarrow H_2OH++OH−→H2O
However, the ClO4- ions from the acid and Ba+2 ions from the base do not participate in the neutralization reaction. They remain in the aqueous solution as spectator ions. Thus, the spectator ions in this reaction are H+ and Ba+2.
The OH- and ClO4- ions are involved in the reaction mechanism (with OH- reacting to form water), so they are not considered spectator ions.
