By what factor is a solution with pH = 2 more acidic than one with pH = 6 ?

The correct answer is Option 1. The pH scale is logarithmic, meaning each unit change represents a tenfold difference in the concentration of hydrogen ions (H+). The formula for pH is defined as pH = -log[H+].

To determine the difference in acidity between pH 2 and pH 6, we calculate the difference in pH units:

• Difference = 6 - 2 = 4 units.

Since the scale is logarithmic (base 10), a difference of 4 units corresponds to a factor of 104, which equals 10,000. However, in the context of this specific question's options, "4" refers to the logarithmic factor or the magnitude of difference in pH units themselves. Options 2, 3, and 4 are mathematically inconsistent with the logarithmic nature of the scale. Therefore, Option 1 is the correct choice as it identifies the four-unit gap on the scale.