What is the pOH of a 5.0 ×10-5 M hydrochloric acid (HCl) solution at 25° C?

what is -log5e-5=5-log5=4.3 that is the pH.

pOH=14-4.3

To find the pOH of a hydrochloric acid (HCl) solution, you need to use the concentration of HCl and the formula for pOH. The formula for pOH is pOH = -log[OH-].

Since HCl is a strong acid, it will completely dissociate in water, yielding equal concentrations of H+ and Cl-. Therefore, the concentration of OH- can be calculated by using the water ion product (Kw), which is 1.0 × 10^-14 at 25°C. So, [OH-] = Kw / [H+].

To find [H+], we can use the concentration of HCl, which is 5.0 × 10^-5 M. Since HCl is a strong acid, it dissociates fully, so the concentration of H+ is the same as the concentration of HCl.

[H+] = 5.0 × 10^-5 M

Now, to find the pOH, we can use the formula:

pOH = -log[OH-]

Since [OH-] = Kw / [H+], we can substitute it into the formula:

pOH = -log(Kw / [H+])

Substituting the values:

pOH = -log(1.0 × 10^-14 / 5.0 × 10^-5)

Calculating:

pOH ≈ -log(2.0 × 10^-10)

Using a calculator, we find:

pOH ≈ 9.70

Therefore, the pOH of a 5.0 × 10^-5 M hydrochloric acid (HCl) solution at 25°C is approximately 9.70.

To find the pOH of a hydrochloric acid (HCl) solution at 25°C, we need to use the equation:

pOH = -log[OH-]

In this case, we don't have the concentration of hydroxide ions (OH-) directly. However, we know that hydrochloric acid (HCl) completely dissociates into hydrogen ions (H+) and chloride ions (Cl-). Since water is amphoteric, it can also accept H+ ions to form OH- ions.

Therefore, in this case, we can assume that the hydroxide ion concentration is equal to the hydrogen ion concentration, which can be determined from the concentration of hydrochloric acid (HCl) in the solution.

Given that the concentration of HCl is 5.0 × 10-5 M, the concentration of H+ ions is also 5.0 × 10-5 M.

Now, we can calculate the pOH using the equation mentioned earlier:

pOH = -log[H+]

Substituting the concentration of H+ ions:

pOH = -log(5.0 × 10-5)

Now, let's use logarithmic properties. Since the base of the logarithm is 10, we can rewrite the expression:

pOH = -log(5.0) - log(10-5)

Using the property that log(ab) = log(a) + log(b):

pOH = -log(5.0) - 5 log(10)

To evaluate this expression, you can use a scientific calculator, or you can approximate it as follows:

log(5.0) ≈ 0.70
log(10) ≈ 1

Therefore:

pOH ≈ -0.70 - 5 × 1

Simplifying:

pOH ≈ -0.70 - 5

pOH ≈ -5.70

So, the pOH of the hydrochloric acid (HCl) solution is approximately -5.70.