A chemist dissolves 455. mg of pure barium hydroxide in enough water to make up 90. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.

A chemist dissolves 423. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.

In carrying out the first standardization in this experiment, a student used 0.5169 g of potassium hydrogen phthalate (KHP) and 24.17 mL of a NaOH solution are needed to reach the equivalence point. What is the concentration (in mol/L) of the student's NaOH solution? Include only the numerical answer (no units). be careful with significant digit

A chemistry student weighs out 0.191 g of lactic acid (HC,H,O,) into a 250. mL volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.0500 M NaOH solution. Calculate the volume of NaOH solution the student will need to add to reach the equivalence point. Round your answer to 3 significant digits. ||mL Ox10