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+] = log7.2 [H+] = -log7.2 [H+] = mc014-1.jpg [H+] = mc014-2.jpg

Answer 1

Answer:

The concentration of the $H^+$ in the solution with pH is $6.3095\times 10^{-8} M$.

Step-by-step explanation:

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

$7.2=-\log[H^+]$

$[H^+]=antilog[-7.2]$

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

$[H^+]=6.3095\times 10^{-8} M$

The concentration of the $H^+$ in the solution with pH is $6.3095\times 10^{-8} M$.

Answer 2

$\bf \textit{Logarithm Cancellation Rules} \\\\ log_a a^x = x\qquad \qquad \boxed{a^{log_a x}=x}\\\\ -------------------------------\\\\ pH=-log(H+)\qquad \stackrel{pH}{7.2}=-log(H+)\implies -7.2=log_{10}(H+) \\\\\\ 10^{-7.2}=10^{log_{10}(H+)}\implies 10^{-7.2}=H+\implies \cfrac{1}{10^{7.2}}=H+$