Final answer:
The solution with a hydronium concentration of 3.0x10^-3 M/L is acidic. This is because the concentration is larger than 1.0 × 10^-7 M, which would correspond to a neutral pH of 7 at 25 °C.
Step-by-step explanation:
If the hydronium concentration in a solution is measured to be 3.0x10^-3 M/L, we can predict whether the solution is acidic, basic, or neutral. The concentration of hydronium ion (H3O+) is a key factor in determining the pH level of a solution. In pure water at 25 °C, the concentration of H3O+ and OH- (hydroxide ion) is 1.0 × 10^-7 M, which gives a neutral pH of 7. A higher concentration of hydronium ion indicates an acidic solution, while a lower concentration indicates a basic solution.
Given a hydronium concentration of 3.0x10^-3 M, which is significantly higher than 1.0 × 10^-7 M, we can determine that the pH is less than 7, as pH = -log[H3O+]. Therefore, the solution is acidic.
In summary, with the given hydronium concentration of 3.0x10^-3 M, the solution would be classified as acidic because the concentration is greater than 1.0 × 10^-7 M and thus the pH is less than 7.