A 20ml hydrochloric acid is diluted by 80ml of distilled water, what would be the pH of the hydrochloric acid after the dilution?
Depends upon the M of the HCl to begin with.
To determine the pH of a solution, you need to know its concentration of hydrogen ions (H+). The hydrochloric acid (HCl) is a strong acid, which means it completely dissociates in water to give H+ ions.
Let's calculate the concentration of the HCl before dilution:
The initial volume of the HCl is 20 mL. Since the HCl is in water, we can assume that the volume remains constant after dilution (100 mL). Therefore, the concentration of HCl is given by:
Initial Concentration (C1) = Volume of HCl / Total Volume
C1 = 20 mL / 100 mL
C1 = 0.2
Now, let's calculate the concentration of the HCl after dilution:
After adding 80 mL of distilled water, the total volume of the solution becomes 100 mL + 80 mL = 180 mL. The concentration can be calculated using the following formula:
Final Concentration (C2) = Initial Concentration (C1) × Initial Volume (V1) / Final Volume (V2)
C2 = 0.2 × 20 mL / 180 mL
C2 = 0.0222
Now that we have the concentration of HCl after dilution, we can calculate the pH. The pH is a measure of the concentration of H+ ions. In this case, the concentration of H+ ions is the same as the concentration of HCl. The pH is given by:
pH = -log10[H+]
pH = -log10(0.0222)
pH = 1.65 (approximately)
Therefore, the pH of the hydrochloric acid after dilution would be approximately 1.65.