Final answer:
The pH level indicates a solution's acidity or basicity. The pH is calculated using the negative logarithm of the hydrogen ion concentration, and a pH of 7 is neutral. Substances like blood (>7) are basic, while others like cherries (<7) are acidic.
Step-by-step explanation:
The pH level is a measure of the acidity or basicity of a solution. This scale ranges from 0 to 14, with 7 being neutral, below 7 acidic, and above 7 basic. The pH of a solution is calculated by taking the negative logarithm of the hydrogen ion concentration ([H+]). For instance, a solution with an [H+] of 1.0 × 10⁻⁴ M will have a pH of 4.00.
Here are examples to determine whether a substance is acidic, basic, or neutral:
- Human blood with a pH of 7.4 is slightly basic because it is above 7.0.
- Household ammonia with a pH of 11.0 is basic.
- Cherries with a pH of 3.6 are acidic.
In a scenario where an aqueous solution has a hydrogen ion concentration of 1.0 × 10⁻⁷M, the solution would be considered neutral as its pH is 7.00.
When adding an acid or base to a buffer solution, the pH may change slightly depending on the buffer's capacity. For example, the pH after adding 3.00 mL of 0.034 M HCl to a buffer can be determined using calculations involving the buffer's components and the amount of acid/base added.