What is the pH of a solution prepared by dissolving 0.15 gram of solid CaO (lime)in enough water to make 2.00 L of aqueous Ca(OH)₂ (limewater)? CaO(s)+ H₂O(l)→ Ca²⁺(aq)+ 2 OH^-(aq) A)2.57 B)2.87 C)11.13 D)11.43

Question

Quizplus · Accepted Answer

First, we must balance the chemical equation: 
CaO(s) + H2O(l) → Ca(OH)2(aq)

Next, we need to determine the number of moles of CaO: 
0.15 g CaO x (1 mol CaO/56.0774 g CaO) = 0.00267 mol CaO

Since CaO is a strong base, it reacts completely with water. Therefore, the number of moles of Ca(OH)2 is also 0.00267 mol.

Finally, we can calculate the pH of the solution using the concentration of hydroxide ions: 
[OH-] = 2 x 0.00267 mol / 2.00 L = 0.00267 M

pOH = -log[OH-] = -log(0.00267) = 2.57 
pH = 14 - pOH = 11.43

Therefore, the pH of the solution is 11.43, so the best choice is D.

What Is the PH of a Solution Prepared by Dissolving