If we have a concentration of H+ at 5 x 10-2 mol/L, what is the pH value?

To find the pH value, we can use the equation:

pH = -log[H+]

First, we need to take the logarithm of the concentration of H+. The concentration given is 5 x 10^(-2) mol/L. To take the logarithm, we can use the base 10 logarithm. Taking the logarithm will give us:

log[H+] = log(5 x 10^(-2))

Next, we can simplify the logarithm using the properties of logarithms:

log(5 x 10^(-2)) = log(5) + log(10^(-2))

Since log(10^(-2)) = -2, the equation becomes:

log(5 x 10^(-2)) = log(5) + (-2)

Now, we can find the logarithm of 5 using a calculator. Taking the logarithm will give us:

log(5) ≈ 0.699

Substituting this value into the equation:

pH = -log[H+] ≈ -0.699 + (-2)

Adding the terms inside the parentheses:

pH ≈ -2.699

Therefore, the pH value is approximately -2.699.