Question

which of the following solutions has the highest concentration of free h+ ions?
o ph 14
o ph 7
o ph 4
o ph 1

Explanation:

Step1: Recall pH - H+ ion concentration relation

The formula for pH is $pH=-\log[H^{+}]$, where $[H^{+}]$ is the concentration of free H+ ions. Rearranging for $[H^{+}]$ gives $[H^{+}]=10^{-pH}$.

Step2: Calculate $[H^{+}]$ for each pH value

For pH = 14, $[H^{+}]=10^{-14}\ M$. For pH = 7, $[H^{+}]=10^{-7}\ M$. For pH = 4, $[H^{+}]=10^{-4}\ M$. For pH = 1, $[H^{+}]=10^{-1}\ M$.

Step3: Compare the values

Since $10^{-1}>10^{-4}>10^{-7}>10^{-14}$, the solution with pH = 1 has the highest concentration of free H+ ions.

Answer:

pH 1