Question

which has the greater concentration of hydrogen ions, a substance with a ph of 5 or a substance with a ph of 4? a ph of 5 is greater. they are both equal; 4 and 5 are relative values. a ph of 4 is greater. ph 9, if you mixed the solutions. there is not enough information to determine the answer.

Explanation:

Step1: Recall pH - hydrogen ion concentration relationship

The formula for pH is $pH = -\log[H^+]$, where $[H^+]$ is the hydrogen - ion concentration. So, $[H^+]=10^{-pH}$.

Step2: Calculate hydrogen - ion concentration for pH = 5

For a substance with pH = 5, $[H^+]_1 = 10^{-5}\ M$.

Step3: Calculate hydrogen - ion concentration for pH = 4

For a substance with pH = 4, $[H^+]_2 = 10^{-4}\ M$.

Step4: Compare the two concentrations

Since $10^{-4}>10^{-5}$, the substance with pH = 4 has a greater hydrogen - ion concentration.

Answer:

C. A pH of 4 is greater.