What is the pH of a 2.5 x 10-6 M solution of HCl?
pH = -log(2.5E-6)
pH = ?
To determine the pH of a solution of HCl, we need to understand what pH represents. pH is a measure of the acidity or alkalinity of a solution and is calculated using the negative logarithm (base 10) of the concentration of hydrogen ions (H+) present in the solution.
In this case, we are given the concentration of HCl as 2.5 x 10^-6 M. Since HCl is a strong acid, it ionizes completely in water, yielding one hydrogen ion for every molecule of HCl. Therefore, the concentration of hydrogen ions, [H+], is the same as the concentration of HCl.
To calculate the pH, we need to take the negative logarithm of the hydrogen ion concentration:
pH = -log[H+]
Substituting the given concentration, we have:
pH = -log(2.5 x 10^-6)
Using the logarithmic property of negative logarithms, we can rewrite the equation as:
pH = log(1 / (2.5 x 10^-6))
Further simplifying by moving the negative sign inside the logarithm, we have:
pH = -log(2.5 x 10^6)
Now, we can evaluate the expression using a calculator or logarithm tables:
pH ≈ -6.60
Therefore, the pH of a 2.5 x 10^-6 M solution of HCl is approximately 6.60.
To find the pH of a solution, we need to use the equation:
pH = -log[H+]
In this case, HCl dissociates in water to form H+ ions. The concentration of H+ ions ([H+]) is equal to the concentration of HCl since HCl dissociates fully in water.
Given that the concentration of the HCl solution is 2.5 x 10^-6 M, we can substitute this value into the equation to find the pH:
pH = -log(2.5 x 10^-6)
Using a calculator, we find:
pH ≈ 5.60
Therefore, the pH of a 2.5 x 10^-6 M solution of HCl is approximately 5.60.