Ion Product Constant of Water

In pure water or dilute aqueous solutions, the product of the hydrogen ion concentration [H⁺] and the hydroxide ion concentration [OH⁻] is a constant, known as…

Syllabus path: Fundamental Chemical Concepts and Calculations › Solution Concentration and pH Calculations

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CSCA Chemistry Formula Reference

Formula and explanation

In pure water or dilute aqueous solutions, the product of the hydrogen ion concentration [H⁺] and the hydroxide ion concentration [OH⁻] is a constant, known as the ion product constant of water K w. Formula: K w = [H⁺][OH⁻] At 25°C, K w = 1.0 × 10⁻¹⁴. Applicable conditions: Applies to aqueous solutions, especially dilute ones. Brief description: This is the fundamental relationship linking the acidity and basicity ( [H⁺] and [OH⁻] ) of a solution. Knowing pH allows calculation of pOH, since pH + pOH = 14 (25°C).

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Solution Concentration and pH Calculations

Core Concepts: Solution Concentration and pH Calculations This section is not only a major area for calculation problems but also the foundation for lab questions (Solution Preparation). In the CSCA exam, the conversion between Molarity and Mass Percentage and pH of Mixtures are …

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