Respuesta :

Answer:

8×10^(-3) mol/L

Explanation:

The formula for finding the hydrogen ion concentration is...

[H⁺] = 10^-ph

[H⁺] = 10^(-2.1)

[H⁺] = 0.00794...mol/L = 8×10^(-3) mol/L

The answer is to 1 significant digit because the pH has one decimal place.