A buffer is prepared by adding 0.15 mol of lactic acid, CH3CHOHCOOH, and 0.20 mol of sodium lactate, Na+CH3CHOHCOO - , to sufficient water to make 1.0 L of buffer solution. The Ka of lactic acid is 1.4 x 10 - 4. Calculate the pH of the buffer.
Ka = 1.4 x 10^-4
pKa = -log Ka
pKa = -log (1.4 x 10^-4 )
pKa = 3.85
pH = pKa + log [sodium lactate / lactic acid ]
pH = 3.85 + log (0.20 / 0.15)
pH = 3.98
A buffer is prepared by adding 0.15 mol of lactic acid, CH3CHOHCOOH, and 0.20 mol of...
9. A buffer solution was prepared by mixing 12.0 mL of 0.12 mol L lactic acid (HLac) with 18.0 mL of 0.16 mol L sodium lactate (NaLac). Kallactic acid) = 1.4 x104. (10 marks) a) Calculate the pH of the solution. Write all relevant chemical equations. State and verify any assumptions you make. 1/6] b) Two 200-ml buffer solutions were prepared with the same pH using different pairs of compounds, as outlined in the table below. Which of these two...
What is the pH of a buffer prepared by adding 6.0 mol of acetic acid and 1 mol of NaOH to water to make a 1.0-L solution? Ka for acetic acid is 1.75*10-5 and its pKa is 4.76.
A buffer is made by adding 0.350 mol lactic acid, CH3CH(OH)COOH, and 0.350 mol potassium lactate, CH3CH(OH)COOK, to enough water to make 1.10 L of solution. The pKa is equal to 4.24. Calculate the pH of this solution after 3.0 mL of 3.0 M KOH is added to the buffer.
A buffer contains 0.010 mol of lactic acid (pKa = 3.86) and 0.050 mol of sodium lactate per liter. (a) Calculate the pH of the buffer. (b) Calculate the change in pH when 5.0 mL of 0.50 M HCl is added to 1.0 L of the buffer. (c) What pH change would you expect if you added the same quantity of HCl to 1.0 L of pure water?
2. (a) Determine the pH of 0.10 M lactic acid (HC3HSO3) (b) What is the pH of a buffer that is 0.12 M. lactic acid and 0.10 M sodium lactate (NaC3H5O3)? For lactic acid. Ka = 1.4 x 10-4. (10)
2.) Consider a 1.00L of buffer that is 0.139M in lactic acid (C3H5O3H) and 0.134M in sodium lactate (C3H5O3- Na+). Calculate the pH of the buffer after adding 0.0500 mol of HCl into the buffer solution. (Assume no volume change) pKa of lactic acid is 3.86
A buffer solution is prepared by mixing 1000mL of 2 0M lacthtc acid with 100.0mL of 20M sodium lactate. This butferis then diluted 1-5 by adding 4ooml of the buffer to 160.0mL of delonized water. the buffer to 160.0mb of deionized water Calculate the volume (in mL) of 2.oM HCI required to change pH of 50.0ml. of this diluted buffer by one pH unit. Ka (lactic acid) 1.38x104
Lactic acid, HC3H5O3, is a substance found in sour milk products such as yogurt, and is produced naturally by fermentation in body cells during normal metabolism and exercise The Ka for lactic acid is 38 x 10-4. Its sodium salt, sodium lactate, NaC3H5O3, is used in foods as a preservative and acidity regulator. It is also used in shampoo products as an effective humectant and moisturizer. Determine the pH of a solution prepared by adding 4.5 grams of sodium lactate...
10Consider a buffer prepared by mixing 15 mL of a .300 M lactic acid (Ka= 1.4x10^-4) and 15 mL of .300 M potassium lactate. Calculate the pH. 2) Calculate the pH of a buffer when 15mL of a 0.150 M sodium hydroxide is mixed with 15 mL of a .300 M lactic acid
10. (a) Determine the pH of 0.10 M lactic acid (HC3H5O3) (b) What is the pH of a buffer that is 0.12 M lactic acid and 0.10 M sodium lactate (NaC2H5O3)? For lactic acid. Ka - 1.4 x 104. (10) 11. Hydrazine, N2H4, is a weak base. Write the equation for the reaction of hydrazine with water and write the expression for Kb. (5) Na Hj