A solution with pH = 4 has
1. relatively high concentration of OH-
2. relatively low concentration of H3O+
3. relatively high concentration of H3O+
4. zero concentration of OH-
pH = 4 has (H^+) = 1E-4.
Then (H^+)(OH^-) = 1E-14
So if (H^+) = 1E-4, then (OH^-) must be 1E-10.
I am still lost? What is the answer 1, 2, 3 or 4?
If I told you that (H^+) = (OH^-) = 1E-7M in pure water, and that in this solution H^+ = 1E-4 and OH^- = 1E-10, then how would you classify (H^+) and (OH^-); i.e., are they relatively large or relatively small.
To determine the correct option, we need to understand the concept of pH.
pH is a measure of the acidity or alkalinity of a solution. It is a logarithmic scale ranging from 0 to 14, with 7 being neutral. pH values below 7 indicate acidity, while values above 7 indicate alkalinity.
In this case, the solution has a pH of 4, which is below 7 and thus considered acidic. Now let's analyze the given options:
1. Relatively high concentration of OH-: A high concentration of hydroxide ions (OH-) would indicate an alkaline solution, which is not the case here. Therefore, this option can be eliminated.
2. Relatively low concentration of H3O+: This option implies that the solution is less acidic, which aligns with the given pH of 4. As pH decreases, the concentration of hydronium ions (H3O+) increases. Therefore, this option is correct.
3. Relatively high concentration of H3O+: This option contradicts the concept of pH. As the pH of a solution decreases, its acidity increases, resulting in higher concentrations of H3O+ ions. Therefore, this option is incorrect.
4. Zero concentration of OH-: A solution with an acidic pH does not have a zero concentration of hydroxide ions (OH-). This option can be eliminated.
In conclusion, option 2 is the correct answer. A solution with a pH of 4 has a relatively low concentration of H3O+.