Final answer:
Seawater, with a pH of 8.5, has the lowest concentration of [H+] ions among the given options because it has the highest pH value, making it the least acidic (more alkaline) solution.
Step-by-step explanation:
To determine which liquid has the lowest concentration of [H+] ions, we must understand the pH scale, which measures the acidity or alkalinity of a solution. The pH scale runs from 0 to 14: a pH less than 7 indicates an acidic solution, a pH of 7 is neutral (like pure water), and a pH greater than 7 indicates a basic or alkaline solution. The concentration of hydrogen ions is inversely related to the pH value; a lower pH means a higher concentration of hydrogen ions.
From the options provided:
-
- Lemon Juice (pH = 2.3) is acidic
-
- Blood (pH = 7.4) is slightly alkaline
-
- Seawater (pH = 8.5) is more alkaline
-
- Coffee (pH = 5.1) is acidic
Comparing these pH values, we can determine that Seawater (pH = 8.5) is the least acidic and therefore has the lowest concentration of [H+] ions among the options given.