Answer:
0.773
Step-by-step explanation:
To find the pH of the solution, we need to determine the concentration of hydroxide ions (OH-) in the solution, as pH is defined as the negative logarithm of the hydrogen ion (H+) concentration, and in a basic solution, the concentration of OH- is greater than that of H+.
First, let's calculate the moles of OH- that will be present in the solution. We can do this by using the following equation:
moles of OH- = concentration x volume
For the KOH solution:
moles of OH- = 0.105 M x 0.00500 L = 0.000525 moles
For the Ca(OH)2 solution:
moles of OH- = 9.5 x 10^-2 M x 0.0150 L x 2 = 0.00285 moles (Note: we multiply by 2 because there are two moles of OH- per mole of Ca(OH)2)
The total moles of OH- in the solution is the sum of the moles from the two solutions:
total moles of OH- = 0.000525 moles + 0.00285 moles = 0.003375 moles
Next, we can calculate the total volume of the solution:
total volume = 5.00 mL + 15.0 mL = 20.0 mL = 0.0200 L
Now we can calculate the concentration of OH-:
OH- concentration = moles of OH- / total volume
OH- concentration = 0.003375 moles / 0.0200 L
OH- concentration = 0.16875 M
Finally, we can find the pH of the solution:
pH = -log[OH-]
pH = -log(0.16875)
pH = 0.773