Show how you calculated how much OH minus would need to be added to 20.0 mL a 0.1 M solution of weak acid to obtain a buffer with the correct pH. pH = 7.1 pKa = 7.21

= く O Acids and Bases Calculating the composition of a buffer of a given pH 0/5 a A chemistry graduate student is given 300. mL of a 0.70 M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K = 4.9 x 10 10. What mass of NaCN should the student dissolve in the HCN solution to turn it into a buffer with pH = 9.48? You may assume that the volume of the solution doesn't change when the NaCN is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. x10 ㅁ

A biochemist has 100 mL of a 0.1 M solution of a weak acid with a pKa of 6.3. She adds 6 mL of 1.0 M HCl, which changes the pH to 5.7. Calculate the pH of the original solution. original solution pH:

Consider the titration of a 60.0 mL of 0.321 M weak acid HA (Ka = 4.2 x 10⁻⁶) with 0.400 M KOH. 1. What is the pH before any base has been added? 2. After 30.0 mL of KOH have been added, identify the primary species left in the solution. 3. After 30.0 mL of KOH have been added, what would the pH of the solution be? 4. After 75.0 mL of KOH have been added, identify the primary species left in the solution. 5. After 75.0 mL of KOH have been added, what would the pH of the solution be?