Final answer:
The pH of the barium hydroxide solution is calculated to be approximately 13.09, showing that it is a strong basic solution.
Step-by-step explanation:
To calculate the pH of the solution containing barium hydroxide, we first need to obtain the molarity of Ba(OH)2. As barium hydroxide (Ba(OH)2) completely dissociates in water, it produces one Ba2+ and two OH- ions for each formula unit dissolved. With 740 mg (or 0.740 g) of Ba(OH)2 and a molar mass of approximately 171.34 g/mol.
We get 0.740 g / 171.34 g/mol = 0.00432 moles of Ba(OH)2. The volume of the solution is 70 mL, which is 0.070 liters, thus the molarity is 0.00432 moles / 0.070 liters = 0.0617 M. Since Ba(OH)2 provides two moles of hydroxide ions for every mole dissolved, the concentration of OH- is 2 x 0.0617 M = 0.1234 M.
The pOH of the solution can be calculated using the formula pOH = -log[OH-], which yields pOH = -log(0.1234) ≈ 0.9087. To obtain the pH, subtract the pOH value from 14, resulting in pH = 14 - 0.9087 = 13.0913. In summary, the pH of the barium hydroxide solution is approximately 13.09, indicating a strong basic solution.