Question

the equation for the ph of a substance is ph = -logh+, where h+ is the concentration of hydrogen ions. what equation models the concentration of hydrogen ions (h+) of a solution whose ph is 7.2?
h+ = log7.2
h+ = -log7.2
h+ = 10 - 7.2
h+ = 107.2

Explanation:

Step1: Use the formula \(pH = -\log[H^{+}]\)

Given \(pH = 7\), substitute into the formula: \(7=-\log[H^{+}]\)

Step2: Solve for \([H^{+}]\)

Multiply both sides by \(- 1\): \(-7=\log[H^{+}]\)
By the definition of logarithm, if \(\log_{10}x = y\), then \(x = 10^{y}\). Here, the base of the common logarithm \(\log\) is \(10\), so \([H^{+}]=10^{-7}\)

Answer:

\([H^{+}]=10^{-7}\) (the second option)