Which of these numbers best represents an alkaline solution?
A.
1
B.
6
C.
7
D.
12
The correct answer and Explanation is :
The number that best represents an alkaline solution is D. 12.
Explanation:
The pH scale measures how acidic or alkaline a solution is, ranging from 0 to 14. This scale is logarithmic, meaning each whole number change represents a tenfold change in hydrogen ion concentration.
- Acidic Solutions: pH values less than 7 indicate acidic solutions. For example, lemon juice and vinegar typically have pH values around 2-3. The lower the pH value, the higher the concentration of hydrogen ions, making the solution more acidic.
- Neutral Solution: A pH of 7 is considered neutral. Pure water at 25°C (77°F) has a pH of 7, meaning it has an equal concentration of hydrogen ions and hydroxide ions. Neutral solutions are neither acidic nor alkaline.
- Alkaline Solutions: pH values greater than 7 indicate alkaline (or basic) solutions. These solutions have a lower concentration of hydrogen ions and a higher concentration of hydroxide ions. For instance, household ammonia and baking soda solutions typically have pH values around 9-10.
In this context, pH 12 is an alkaline solution. This high pH value signifies a strong base, indicating a significant excess of hydroxide ions compared to hydrogen ions. Examples of substances with a pH around 12 include certain cleaning agents like bleach or lime solutions.
To summarize, on the pH scale, values above 7 indicate alkalinity. Given the options, 12 is the highest and thus best represents an alkaline solution.