On the pH scale at $25°C$, a solution with $\mathrm{pH}=7$ is best described as:

• A. Acidic
• B. Neutral
• C. Strongly acidic
• D. Basic

Answer: (B)

Verified step by step guidance

1. Recall that the pH scale measures the acidity or basicity of a solution, where pH is defined as \(\mathrm{pH} = -\log[\mathrm{H}^+]\), with \([\mathrm{H}^+]\) being the concentration of hydrogen ions in moles per liter.
2. Understand that at 25°C, pure water has a neutral pH of 7 because the concentrations of hydrogen ions \([\mathrm{H}^+]\) and hydroxide ions \([\mathrm{OH}^-]\) are equal, each being \$1 \times 10^{-7}$ M.
3. Recognize that a pH less than 7 indicates an acidic solution (higher \([\mathrm{H}^+]\)), and a pH greater than 7 indicates a basic (alkaline) solution (lower \([\mathrm{H}^+]\)).
4. Since the given solution has a pH of exactly 7 at 25°C, it means the solution is neither acidic nor basic but neutral, with equal concentrations of \([\mathrm{H}^+]\) and \([\mathrm{OH}^-]\).
5. Therefore, the correct description of a solution with pH = 7 at 25°C is 'Neutral'.