calculate the pH of 20.00mL of 2.00 M HCl diluted to 0.500 L

(HCl) = 2.00 M x (20 mL/500 mL) = ?

Then convert to pH.

To calculate the pH of a solution, you need to know the concentration of the acidic or basic compound and the dissociation constant of that compound. In the case of hydrochloric acid (HCl), it is a strong acid and fully dissociates in water.

First, let's determine the moles of HCl in the solution. We can use the formula:

moles = concentration × volume

Given:
Concentration of HCl = 2.00 M (= 2.00 mol/L)
Volume of HCl = 20.00 mL (= 0.02000 L)

moles of HCl = 2.00 M × 0.02000 L = 0.0400 mol

Now, we need to calculate the molarity of the diluted solution. We can use the formula:

M1 × V1 = M2 × V2

Given:
M1 = 2.00 M (initial concentration of HCl)
V1 = 0.02000 L (initial volume of HCl)
M2 = Unknown (diluted concentration of HCl)
V2 = 0.500 L (final volume of the solution)

2.00 M × 0.02000 L = M2 × 0.500 L
0.0400 mol = M2 × 0.500 L
M2 = 0.0400 mol ÷ 0.500 L = 0.0800 M

Now that we know the concentration of the diluted solution is 0.0800 M, we can calculate the pH. For a strong acid like HCl, the pH is determined solely by the concentration of H+ ions, which is equal to the concentration of the acid.

Hence, the pH of the solution is -log(0.0800) = 1.10 (rounded to two decimal places).

Therefore, the pH of 20.00 mL of 2.00 M HCl diluted to 0.500 L is approximately 1.10.