Question

which statement best describes the difference between a substance with a ph of 3.0 and a substance with a ph of 6.0? (1 point)
the substance with the higher ph has twice as many hydrogen ions per volume of water.
the substance with the lower ph has 1,000 times as many hydrogen ions per volume of water.
the substance with the lower ph has twice as many hydrogen ions per volume of water.
the substance with the higher ph has 1,000 times as many hydrogen ions per volume of water.

Explanation:

Step1: Recall pH formula

The pH is defined as $pH = -\log[H^+]$, where $[H^+]$ is the hydrogen - ion concentration in moles per liter.

Step2: Calculate $[H^+]$ for pH = 3.0

If $pH = 3.0$, then $[H^+]_1=10^{-3}$ moles per liter since $3.0=-\log[H^+]_1$, so $[H^+]_1 = 10^{-3}$.

Step3: Calculate $[H^+]$ for pH = 6.0

If $pH = 6.0$, then $[H^+]_2=10^{-6}$ moles per liter since $6.0 = -\log[H^+]_2$, so $[H^+]_2=10^{-6}$.

Step4: Find the ratio of $[H^+]_1$ to $[H^+]_2$

$\frac{[H^+]_1}{[H^+]_2}=\frac{10^{-3}}{10^{-6}}=10^{(- 3-(-6))}=10^{3}=1000$. The substance with pH = 3.0 (lower pH) has 1000 times as many hydrogen ions per volume of water as the substance with pH = 6.0.

Answer:

The substance with the lower pH has 1,000 times as many hydrogen ions per volume of water.