EXPLANATION
GS9. What is the pH value of pure water?
a) 5
b) 7
c) 10
d) 14
ANSWER: b) 7
EXPLANATION:
The pH value of pure water is b) 7.
pH is a scale that measures how acidic or alkaline a substance is. A pH of 7 is neutral, meaning that the substance is neither acidic nor alkaline. A pH below 7 is acidic, while a pH above 7 is alkaline(basic).
Pure water is a neutral substance, so its pH is 7. However, pure water is rarely found in nature. Most water contains dissolved minerals and gases, which can alter its pH. For example, rainwater is slightly acidic due to the dissolved carbon dioxide in the air.
