Final Answer:
The pH of a solution prepared by dissolving 4 g of Ca(OH)2 in water to make 945 mL of solution is approximately 10.74.
Step-by-step explanation:
The pH of a solution is determined by the concentration of hydrogen ions (H+) in the solution.
In the case of a basic solution like one formed by dissolving Ca(OH)2 (calcium hydroxide), we need to consider the hydroxide ions (OH-) concentration.
First, calculate the moles of Ca(OH)2 using its molar mass. Then, determine the concentration of OH- ions in the solution.
Since Ca(OH)2 dissociates into two OH- ions per molecule, multiply the moles of Ca(OH)2 by 2 to get the moles of OH- ions.
Next, calculate the pOH using the formula: pOH = -log[OH-]. Finally, find the pH using the relationship: pH = 14 - pOH.
In this specific case, the calculation results in a pH of approximately 10.74, indicating a basic solution.
The presence of hydroxide ions from the dissociation of Ca(OH)2 contributes to the alkaline nature of the solution.