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Chemistry

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Analytical Chemistry

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Chemical Equilibria

Water Ionization and Kw in Equilibrium

Description

Water ionization and the ionic product of water describe how pure water reaches equilibrium. Water is a weak electrolyte, so only a small amount breaks into hydrogen ions and hydroxide ions. At a fixed temperature, the amount of undissociated water stays almost constant.

Because of this, the ioni...

Transcript

水是一种弱电解质,会发生少量的自电离。

在任何给定温度下,未解离水的浓度被视为恒定,因此水的离子积 Kw 是氢离子和氢氧根离子浓度的乘积。

Kw 随温度升高而增大。在 25 °C 时,纯水的 Kw 为 10−14

在这些条件下,纯水中氢离子和氢氧根离子的浓度相等,因此单个离子的浓度等于 Kw 的平方根。

中性溶液含有等浓度的这些离子。

假设氢离子浓度大于 10−7,则该溶液被视为酸性;而低于此值时,溶液为碱性或碱性...

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