Question

Calculate the [H*] if the pH = 12.1

Answer 1

7.94 × 10^-13 M

Step-by-step explanation:

The pH scale is used to measure how acidic or basic a solution is, ranging from values of 0 to 14. A pH of 7 is neutral, and pHs less than 7 are more acidic while pHs greater than 7 are more basic. The acidity of a solution is based on the concentration of hydrogen, or H+, ions. Acidic solutions have a higher concentration of H+ ions while basic solutions have a lower concentration of H+ ions and more hydroxyl (OH-) ions.

The pH of a solution can be calculated by taking the negative log of the H+ ion: pH = -log[H+]

We can rearrange this equation to solve for the H+ concentration. We divide both sides by -1 and then cancel out the log by by raising both sides to an exponent with base 10.

• -pH = log[H+]
• 
  `10^(-pH) = [H^(+)]`
• 
  `[H^(+)]= 10^(-pH)`

Now plug in the value for pH into the equation and solve.

• 
  `[H^(+)]= 10^(-12.1)`
• [H+] = 7.94328235 × 10^-13

* Concentration is expressed as mol/L or M.

The [H+] is approximately 7.94 × 10^-13 M.