Calculate the pH of 3.9 10-8 M HNO3.

HNO3 is a strong acid so the H^+ concn is the same as the HNO3 concn. Convert that to pH.

To calculate the pH of a solution, you need to know the concentration of hydronium ions (H3O+). In this case, we are given the concentration of nitric acid (HNO3).

Nitric acid, HNO3, is a strong acid that completely dissociates in water, which means it ionizes into H+ (proton) and NO3- (nitrate) ions. So, each molecule of HNO3 produces one H+ ion.

Given that the concentration of HNO3 is 3.9 x 10^-8 M, this means the concentration of H+ ions is also 3.9 x 10^-8 M.

The pH of a solution is defined as the negative logarithm (base 10) of the hydronium ion concentration, so we can use the equation:

pH = -log10[H+]

Plugging in the value of the concentration:

pH = -log10(3.9 x 10^-8)

To calculate this, you can use a scientific calculator or follow the steps below:

1. Take the negative logarithm (base 10) of the concentration: log10(3.9 x 10^-8) = -8 - log10(3.9).

2. Calculate the logarithm of 3.9: log10(3.9) ≈ 0.59106.

3. Subtract the value from step 2 from -8: -8 - 0.59106 = -8.59106.

Therefore, the pH of a 3.9 x 10^-8 M HNO3 solution is approximately 8.6.