Question

The pH of a solution is 3. What is the concentration of hydrogen ions in this solution?

• A. 1 × 10$^{-3}$ M
• B. 3 × 10$^{-4}$ M
• C. 10$^{-3}$ M
• D. 10$^{-3}$ M

Hint:

pH is a logarithmic scale where pH = $-\log_{10} [H^+]$.
A pH of 3 corresponds to $[H^+]$ = 10$^{-3}$ M.
Always check the exponent and coefficient in options.