Concept:Quicklime is a basic oxide that raises the pH of water.
Explanation:Quicklime is chemically calcium oxide,
CaO.
When added to water, it reacts to form slaked lime,
Ca(OH)2, which is a strong base.
The reaction is:
CaO+H2O→Ca(OH)2.
This base increases the hydroxide ion concentration, making the solution alkaline.
Therefore, the pH becomes greater than 7.
Among the given options, the only pH above 7 is 8.
Answer:D. 8