Question

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

\\(\text{h}^+ = \log 7.2\\)
\\(\text{h}^+ = -\log 7.2\\)
\\(\text{h}^+ = 10^{-7.2}\\)
\\(\text{h}^+ = 10^{7.2}\\)

Explanation:

Substitute the given pH value

Using the pH Scale Calculations knowledge point

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

Isolate the logarithm term

Using the pH Scale Calculations knowledge point

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

Convert to exponential form

Using the Logarithmic and Exponential Inverses knowledge point

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

Answer:

• (A) \([H^+] = \log 7.2\)
• (B) \([H^+] = -\log 7.2\)
• (C) \([H^+] = 10^{-7.2}\) (Correct answer)
• (D) \([H^+] = 10^{7.2}\)