If a solution A has 10,000 times as many H+ ions as solution B, what is the difference in pH units between the two solutions?

To determine the difference in pH units between two solutions, you need to understand the concept of pH and how it is calculated.

pH is a measure of the acidity or basicity of a solution and is defined as the negative logarithm (base 10) of the concentration of hydrogen ions (H+). The pH scale ranges from 0 to 14, with values below 7 indicating acidity, values above 7 indicating alkalinity (basicity), and a pH of 7 representing neutrality. Each unit on the pH scale represents a ten-fold difference in the concentration of H+ ions.

In this case, solution A has 10,000 times as many H+ ions as solution B. This means that the concentration of H+ ions in solution A is 10,000 times greater than the concentration in solution B.

To quantify the difference in pH units between the two solutions, we need to calculate the ratio of the H+ ion concentrations:

pH(A) - pH(B) = log10(concentration of H+ in solution A / concentration of H+ in solution B)

Since solution A has 10,000 times as many H+ ions as solution B, we can substitute the ratio into the equation:

pH(A) - pH(B) = log10(10,000)

To simplify, we know that log10(10,000) = log10(10^4) = 4.

Therefore, the difference in pH units between the two solutions is 4.