Final answer:
The solution with a hydrogen ion concentration of 6.8 × 10⁻³ M is acidic because it exceeds the neutral concentration of 1 × 10⁻· M.
Step-by-step explanation:
A solution has a hydrogen ion concentration of 6.8 × 10⁻³ M. To determine whether this solution is acidic, basic, or neutral, we need to compare it to the standard neutral hydrogen ion concentration of 1 × 10⁻· M. In the case of a solution with a hydrogen ion concentration greater than 1 × 10⁻· M, the solution is considered acidic. Since 6.8 × 10⁻³ M is greater than 1 × 10⁻· M, the solution in question is indeed acidic.
As a supplemental note, the term 'basic' refers to solutions with a hydrogen ion concentration less than 1 × 10⁻· M, and 'neutral' refers to solutions where the hydrogen ion concentration is exactly 1 × 10⁻· M. The term 'alkaline' is often used interchangeably with 'basic' and pertains to the same property of having a low hydrogen ion concentration. Therefore, based on the provided hydrogen ion concentration, the correct option is a) Acidic.