Question

complete the following table for a solution at ( 25^{circ} mathrm{c} ).

Explanation:

Step1: Recall the pH formula

The formula for pH is \(pH = -\log[H_3O^+]\). When \(pH<7\), we can solve for \([H_3O^+]\) using the inverse formula \([H_3O^+]=10^{-pH}\). Since \(pH < 7\), then \(10^{-pH}>10^{-7}\), so \([H_3O^+]> 1.0\times10^{-7}\text{ M}\). And a solution with \(pH<7\) is acidic.

Step2: Analyze \(pH > 7\) case

Using \(pH = -\log[H_3O^+]\), when \(pH>7\), then \([H_3O^+]=10^{-pH}<10^{-7}\), so \([H_3O^+]<1.0\times 10^{-7}\text{ M}\). And a solution with \(pH > 7\) is basic.

Step3: Analyze \(pH=7\) case

When \(pH = 7\), using \(pH=-\log[H_3O^+]\), we have \([H_3O^+]=10^{-7}\text{ M}\), and the solution is neutral.

Answer:

pH	\([H_3O^+]\)	Solution is
\(>7\)	\(<1.0\times 10^{-7}\text{ M}\)	Basic
\(=7\)	\(=1.0\times 10^{-7}\text{ M}\)	Neutral