To determine the spectator ions in the given complete ionic equation, we need to identify the ions that remain unchanged on both sides of the equation. Let's analyze the equation step by step:
The complete ionic equation is:
[tex]\[
H ^{+}( aq )+ Br ^{-}( aq )+ K ^{+}( aq )+ OH ^{-}( aq ) \rightarrow H _2 O ( l )+ K ^{+}( aq )+ Br ^{-}( aq )
\][/tex]
1. Identify the ions on both sides of the equation:
Left side:
[tex]\[
H ^{+}( aq ) + Br ^{-}( aq ) + K ^{+}( aq ) + OH ^{-}( aq )
\][/tex]
Right side:
[tex]\[
H _2 O ( l ) + K ^{+}( aq ) + Br ^{-}( aq )
\][/tex]
2. Determine which ions appear on both sides without any change:
- [tex]\(H ^{+} (aq)\)[/tex] and [tex]\(OH ^{-} (aq)\)[/tex] combine to form water [tex]\(H_2O (l)\)[/tex].
- [tex]\(K ^{+} (aq)\)[/tex] appears on both sides in aqueous form.
- [tex]\(Br ^{-} (aq)\)[/tex] appears on both sides in aqueous form.
3. Identify the ions that remain unchanged:
- [tex]\(K ^{+} (aq)\)[/tex] remains unchanged.
- [tex]\(Br ^{-} (aq)\)[/tex] remains unchanged.
These ions do not participate in the actual chemical reaction but remain in the solution in their ionic form. Such ions are called spectator ions.
4. Select the correct spectator ion from the provided options:
The given options are:
- [tex]\(H _2 O\)[/tex]
- [tex]\(OH ^{-}\)[/tex]
- [tex]\(K ^{+}\)[/tex]
- None of the answers are correct
- [tex]\(H ^{+}\)[/tex]
From the options, [tex]\(K ^{+} (aq)\)[/tex] is indeed a spectator ion. It remains unchanged and does not take part in the reaction itself.
Therefore, the correct spectator ion from the options given is:
[tex]\[
\boxed{K ^{+}}
\][/tex]
