To determine the correct dissociation reaction for [tex]\( \text{Na}_2\text{SO}_4 \)[/tex] in water, we need to understand what happens when sodium sulfate dissolves. Sodium sulfate ([tex]\( \text{Na}_2\text{SO}_4 \)[/tex]) dissociates into its constituent ions when dissolved in water.
1. Sodium sulfate ([tex]\( \text{Na}_2\text{SO}_4 \)[/tex]) consists of two sodium ions ([tex]\( \text{Na}^+ \)[/tex]) and one sulfate ion ([tex]\( \text{SO}_4^{2-} \)[/tex]).
2. When it dissolves, the ions separate completely in the aqueous solution.
Let's examine the given reactions:
1. [tex]\( \text{Na}_2\text{SO}_4(s) \rightarrow 2 \text{Na}^+(aq) + \text{SO}_4^{2-}(aq) \)[/tex]
2. [tex]\( \text{Na}_2\text{SO}_4(s) \rightarrow \text{Na}^+(aq) + \text{SO}_4^{2-}(aq) \)[/tex]
3. [tex]\( \text{Na}_2\text{SO}_4(s) \rightarrow \text{Na}(aq) + \text{SO}_4(aq) \)[/tex]
4. [tex]\( \text{Na}_2\text{SO}_4(s) \rightarrow 2 \text{Na}(aq) + \text{SO}_4(aq) \)[/tex]
Comparing these reactions:
- The correct dissociation reaction should show sodium sulfate ([tex]\( \text{Na}_2\text{SO}_4 \)[/tex]) dissociating into two sodium ions ([tex]\( \text{Na}^+ \)[/tex]) and one sulfate ion ([tex]\( \text{SO}_4^{2-} \)[/tex]).
- Each sodium ion is represented as [tex]\( \text{Na}^+(aq) \)[/tex], indicating it is in the aqueous phase.
- The sulfate ion is represented as [tex]\( \text{SO}_4^{2-}(aq) \)[/tex].
Thus, the correct dissociation reaction is:
[tex]\[ \text{Na}_2\text{SO}_4(s) \rightarrow 2 \text{Na}^+(aq) + \text{SO}_4^{2-}(aq) \][/tex]
This matches the standard behavior of sodium sulfate when it dissociates in water, confirming the correct dissociation reaction.
