Question

the equation for the ph of a substance is ph = - log h+, where h+ is the concentration of hydrogen ions. which equation models the concentration of hydrogen ions (h+) of a solution whose ph is 7.2? h+ = - log 7.2 h+ = log 7.2 h+ = 10^7.2 h+ = 10^(-7.2)

Explanation:

Step1: Start with given formula

$pH = -\log[H^{+}]$

Step2: Substitute pH value

Given $pH = 7.2$, so $7.2=-\log[H^{+}]$.

Step3: Solve for $[H^{+}]$

Multiply both sides by - 1: $-7.2=\log[H^{+}]$.
By the definition of a logarithm, if $\log_{10}a = b$, then $a = 10^{b}$. Here the base of the logarithm is 10 (common - log), so $[H^{+}]=10^{-7.2}$.

Answer:

$[H^{+}]=10^{-7.2}$