Calculate the [H+] in a solution that has a pH of 9.00.

See your post above.

To calculate the [H+] (hydronium ion concentration) in a solution with a given pH, you can use the equation:

[H+] = 10^(-pH)

In this case, the pH is given as 9.00. So, plug this value into the equation:

[H+] = 10^(-9.00)

To evaluate this, you can use a calculator or follow these steps:

1. Take the negative value of the given pH: -9.00
2. Calculate 10 to the power of -9.00: 10^(-9.00) = 1 x 10^(-9)

Therefore, the [H+] concentration in the solution with a pH of 9.00 is 1 x 10^(-9) or simply 1 nanomolar (nM).