Which of the following is correct regarding the pH scale?
A.
A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4
B.
A substance with a pH of 3 is two times more acidic than a substance with a pH of 4
C.
A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4
D.
A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4
The correct statement regarding the pH scale is: a. A substance with a pH of 3 is 10 times as acidic as a substance with a pH of 4. Explanation: 1. The pH scale is a measure of how acidic or basic (alkaline) a substance is. It ranges from 0 to 14, with 7 being neutral, below 7 being acidic, and above 7 being basic. 2. Each whole pH value below 7 is 10 times more acidic than the next higher value. Similarly, each whole pH value above 7 is 10 times more basic than the next lower value. 3. In this case, the difference between a pH of 3 and 4 is 1 unit. Since each unit represents a factor of 10 in acidity, a substance with a pH of 3 is indeed 10 times as acidic as a substance with a pH of 4. Therefore, the correct statement is that a substance with a pH of 3 is 10 times as acidic as a substance with a pH of 4.
Final answer:
A substance with a pH of 3 is 10 times as acidic as a substance with a pH of 4, due to the logarithmic nature of the pH scale. Thus, the correct option is a) A substance with a pH of 3 is 10 times as acidic as a substance with a pH of 4.
Explanation:
The correct answer regarding the pH scale is: ‘A substance with a pH of 3 is 10 times as acidic as a substance with a pH of 4.’ This is because the pH scale is a logarithmic scale measuring the concentration of hydrogen ions ([H+]) in a substance. For each unit change in pH, the acidity or basicity of a solution changes tenfold. Thus, a substance with a pH of 3 has 10 times more [H+] than a substance with a pH of 4, making it 10 times more acidic.