Determine the pH of a solution made by mixing 50,00 mL of 0,100 M nitric acid with 100 mL of 0,200 M nitric acid
To determine the pH of a solution made by mixing different concentrations of a common acid, you need to consider the principles of acid-base chemistry. In this case, the two concentrations of nitric acid can be combined to calculate the resulting pH using the following steps:
Step 1: Calculate the number of moles for each solution.
Moles = concentration (M) × volume (L)
For the first solution:
Moles of 0.100 M nitric acid = 0.100 mol/L × 0.05000 L = 0.005 moles
For the second solution:
Moles of 0.200 M nitric acid = 0.200 mol/L × 0.100 L = 0.020 moles
Step 2: Determine the total moles of nitric acid in the combined solution.
Total Moles = Moles of first solution + Moles of second solution
Total Moles = 0.005 moles + 0.020 moles = 0.025 moles
Step 3: Calculate the volume of the resulting solution.
Volume = Volume of first solution + Volume of second solution
Volume = 0.05000 L + 0.100 L = 0.150 L
Step 4: Calculate the new concentration of the combined solution.
Concentration (M) = Total Moles / Volume
Concentration = 0.025 moles / 0.150 L = 0.1667 M
Step 5: Calculate the pH using the concentration of the combined solution.
pH = -log[H+]
[H+] is the concentration of hydrogen ions.
In this case, since the nitric acid dissociates to form one hydrogen ion (H+), the concentration of hydrogen ions is the same as the concentration of nitric acid solution.
pH = -log(0.1667) ≈ 0.778
Therefore, the pH of the solution made by mixing 50.00 mL of 0.100 M nitric acid with 100 mL of 0.200 M nitric acid is approximately 0.778. Note that the answer is rounded to three decimal places.