Which statement about pH is true?

Which statement about pH is true?

• A. Higher pH indicates higher acidity.
• B. Lower pH indicates higher acidity.
• C. pH does not relate to acidity.
• D. Neutral pH is acidic.

Answer: (B)

Acidity is about how many hydrogen ions are in a solution, and pH is a measure of that hydrogen ion concentration. The pH scale runs 0 to 14, where lower numbers mean more hydrogen ions (more acidic), a pH of 7 is neutral, and higher numbers mean fewer hydrogen ions (more basic). Because pH is the negative logarithm of [H+], a small drop in pH corresponds to a large increase in acidity. So, a lower pH indicates higher acidity because as hydrogen ion concentration rises, the solution becomes more acidic and the pH value falls. For example, lemon juice is highly acidic with a low pH, while pure water is near neutral around 7, and common cleaners are much more basic with high pH. This makes the statement about lower pH and higher acidity the true one. The other options contradict how pH reflects hydrogen ion concentration: higher pH corresponds to less acidity, pH is related to acidity, and neutral pH is not acidic.

Acidity is about how many hydrogen ions are in a solution, and pH is a measure of that hydrogen ion concentration. The pH scale runs 0 to 14, where lower numbers mean more hydrogen ions (more acidic), a pH of 7 is neutral, and higher numbers mean fewer hydrogen ions (more basic). Because pH is the negative logarithm of [H+], a small drop in pH corresponds to a large increase in acidity.

So, a lower pH indicates higher acidity because as hydrogen ion concentration rises, the solution becomes more acidic and the pH value falls. For example, lemon juice is highly acidic with a low pH, while pure water is near neutral around 7, and common cleaners are much more basic with high pH.

This makes the statement about lower pH and higher acidity the true one. The other options contradict how pH reflects hydrogen ion concentration: higher pH corresponds to less acidity, pH is related to acidity, and neutral pH is not acidic.