The pH of an acidic solution changes from 3 to 6. What happens to acidity?
Answer and explanation
Correct answer: It decreases one thousand times
The governing concept is the logarithmic pH scale, defined as pH = −log[H+]. A rise of one pH unit means a tenfold decrease in hydrogen-ion concentration. The change from pH 3 to pH 6 is three units, so acidity decreases by 10 × 10 × 10 = 1000 times. Thus option A is correct. Option B treats pH as an ordinary linear scale, while C and D reverse or ignore the change.
Frequently asked questions
What is the correct answer to this question?
It decreases one thousand times
Why is this the correct answer?
The governing concept is the logarithmic pH scale, defined as pH = −log[H+]. A rise of one pH unit means a tenfold decrease in hydrogen-ion concentration. The change from pH 3 to pH 6 is three units, so acidity decreases by 10 × 10 × 10 = 1000 times. Thus option A is correct. Option B treats pH as an ordinary linear scale, while C and D reverse or ignore the change.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
