Which among the following statements with regard to pH scale is/are correct? I. It is a logarithmic: scale II. The scale is limited to 0-14 because the ionic product of water is about 10~14. III. The lower the value of pH, the greater is the acidity of the solution. Select the correct answer using the code given below

The pH scale is a logarithmic scale used to specify the acidity or basicity of an aqueous solution [t1][t4]. It is defined as the negative logarithm of the hydrogen ion concentration (-log[H+]), meaning each unit change represents a ten-fold change in acidity [t2][t5]. Statement I is therefore correct. Statement II is correct because the standard 0-14 range is derived from the autoionization of water; at 25°C, the ionic product of water (Kw) is approximately 10^-14, which sets the neutral point at 7 and the typical bounds of the scale [t5][t8]. Statement III is also correct as pH and acidity are inversely related: a lower pH value indicates a higher concentration of hydrogen ions, thus representing greater acidity [t1][t3]. Consequently, all three statements are scientifically accurate within the context of standard chemistry.

Sources

1. [1] https://www.epa.gov/system/files/documents/2021-07/parameter-factsheet_ph.pdf
2. [2] https://www.waterboards.ca.gov/water_issues/programs/swamp/docs/cwt/guidance/3140en.pdf
3. [3] https://www.usgs.gov/media/images/ph-scale-0
4. [4] https://www.khanacademy.org/science/biology/water-acids-and-bases/acids-bases-and-ph/a/acids-bases-ph-and-bufffers