Answer :
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.