Calculate how to prepare 750 ml of 0.25 M sodium formate buffer at pH 4. Use your textbook to determine the molecular weight and pKa of the acid and base. Calculate the grams of sodium formate and number of milliliters of formic acid required. THEN using this stock solution, calculate and describe how you would prepare 100 ml of a 10 mM formate buffer, pH 3.5. By the way, what is the molarity of formic acid?
Calculate how to prepare 750 ml of 0.25 M sodium formate buffer at pH 4. Use...
Describe the preparation of 2 liters of 0.25 formate buffer, pH 4.5, starting with 1M formic acid and solid sodium formate (HCOONa). pKa of HCOOH, formic acid is 3.75
Starting from 0.5 M formic acid and solid sodium formate. Describe how to prepare 5 L of Formate buffer, pH = 4, Ka =1.78×10-4
Calculate how to prepare 200 mL of a 0.1 M sodium phosphate buffer at pH 6.8 by combining two separate solutions of 0.1 M NaH2PO4.2H2O and Na2HPO4)? Molecular weight NaH2PO4.2H2O = 156 g/mol; molecular weight Na2HPO4: 141.96 g/mol. Use 6.86 as the pKa and prepare 250 mL of the separate solutions.
You and your lab partner must prepare a 1.0 L buffer of formic acid at pH 3.5. Your lab partner started the process and has already massed out 0.23 g of formic acid (MM 46 g/mol). How many moles of sodium formate do you need to complete this buffer. The pKa of formic acid is 3.75.
how many grams of sodium formate must be dissolved in a 0.300 M solution of formic acid to make 400.0 ml of a buffer solution with a pH=4.60?
2. A Student wants to prepare 250.0 mL of pH 4.1 buffer solution. He is planning to use formic acid (HCOOH) and sodium formate (HCOONa) for this job. What should the mass of sodium formate that he should add to 250,0 mL of 0.20 M formic acid solution to prepare this buffer? (K =1.8x10 for formic acid.) 3. If 0.10 M solution of a weak acid has a pH of 3.90, find the Ka for the acid.
How many grams of sodium formate (NaCHO2) need to be dissolved in 179 mL of a 0.89 M formic acid (pKa= 3.75) solution, so that the concentration of formate equals the concentration of formic acid? Report your answer to two (2) decimal places.
4. Briefly explain the meaning of the term buffer capacity". A formic acid/sodium formate solution would be expected to buffer around what pH (use your textbook)? a) Calculate the pH for a solution containing 3.48 M CSHSN and 2.52 M C H NHBr. (Kb - 1.40 x 10" for CsH:N) Calculate the pH after 150.0 mL of 3.16 M HCl is added to 875.0 mL of the solution in part a) above.
How many grams of sodium formate, NaCHO2, would have to be dissolved in 3.0 L of 0.12 M formic acid (pKa 3.74) to make the solution a buffer for pH 5.30?
3. (5 pts) Find mass of sodium formate to be added to 25.0 mL of 0.25 M solution of formic acid so that after dilution to 100.0 mL the resulting solution has pH = 4.0. The acid dissociation constant of formic acid is 1.8x10".