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Why is H3O+ used instead of a free H+ ion in water?

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sodium sulfate — acid–base reaction Sodium sulfate, also called Glauber's salt, is, like other salts, the product of an acid-base reaction.

In chemistry, a free hydrogen ion ( $H^{+}$ )—which is essentially a bare proton—cannot exist in an aqueous solution because it is highly reactive and readily combines with other particles. When an acid is dissolved in water, the proton does not remain isolated; instead, it becomes strongly attached to a water molecule to form the hydronium ion ( $H_{3} O^{+}$ ).123

This interaction occurs because the proton is a small, positively charged nucleus that seeks stability by bonding with the lone electron pairs of a water molecule. While chemists often use the symbol $H^{+}$ as a convenient shorthand to represent the acidic species in a solution, it is understood that this ion actually exists in a hydrated state as $H_{3} O^{+}$ (or more complex clusters like $H (H_{2} O)_{n}^{+}$ ) when in water. Consequently, the hydronium ion is the accurate representation of the hydrogen ion in aqueous environments.1324