The concentration of hydrogen ion of a sample of vinegar : 1.514 x 10⁻⁷
pH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.
A solution whose value is different by n has a difference in the concentration of H⁺ ion of 10ⁿ.
pH = - log [H⁺]
pH of a sample vinegar = 6.82
The concentration of hydrogen ion :
[tex]\tt 6.82=-log[H^+]\\\\(H^+]=10^{-6.82}=1.514\times 10^{-7}[/tex]