Question

ph measures the acidity of a substance, and is described by the equation ph = -log(h+), where h+ is the concentration of hydrogen ions. human skin has a ph of 5.5. what is its concentration of h+? a 3.16×10^(-6) b 3.16×10^5 c 4.09×10^(-3) d 2.45×10^2

Explanation:

Step1: Rearrange pH formula

Given $pH = -\log(H^{+})$, we can rewrite it as $H^{+}=10^{-pH}$.

Step2: Substitute pH value

Since $pH = 5.5$, then $H^{+}=10^{- 5.5}$.
We know that $10^{-5.5}=10^{0.5}\times10^{-6}$. And $10^{0.5}=\sqrt{10}\approx3.16$, so $H^{+}=3.16\times10^{-6}$.

Answer:

A. $3.16\times10^{-6}$