Use the Henderson Hasselbach equation to determine how much sodium formate (HCOONa, 68.0069 g/mol) should be added to 400 ml of 1M formic acid to make this buffer have a pH = 3.500. (Ka = 1.77 x 10^-4)

You want to make a buffer with a pH of 10.00 from NH4+/NH3. (a) What must the [ NH4+ ]/[ NH3 ]ratio be? (b) How many moles of NH4Cl must be added to 465 mL of an aqueous solution of 1.24 M NH3 to give this pH? (c) How many milliliters of 0.236 M NH3 must be added to 2.08 g of NH4Cl to give this pH? (d) What volume of 0.499 M NH3 must be added to 395 mL, of 0.109 M NH4Cl to give this pH?

When 40.00 mL of a weak monoprotic acid solution is titrated with 0.100-M NaOH, the equivalence point is reached when 35.00 mL base has been added. After 20.00 mL NaOH solution has been added, the titration mixture has a pH of 5.75. Calculate the ionization constant of the acid.

Ka for formic acid is 1.7 104 at 25C. A buffer is made by mixing 529 mL of 0.465 M formic acid, HCHO2, and 494 mL of 0.524 M sodium formate, NaCHO2. Calculate the pH of this solution at 25C after 110 mL of 0.152 M HCl has been added to this buffer.

A sodium hydrogen carbonate-sodium carbonate buffer is to be prepared with a pH of 9.40. (a) What must the [ HCO3 ]/[ CO32 ]ratio be? (b) How many moles of sodium hydrogen carbonate must be added to a liter of 0.225 M Na2CO3 to give this pH? (c) How many grams of sodium carbonate must be added to 475 mL of 0.336 M NaHCO3 to give this pH? (Assume no volume change.) (d) What volume of 0.200 M NaHCO3 must be added to 735 mL of a 0.139 M solution of Na2CO3 to give this pH? (Assume that volumes are additive.)

If added to 1 L of 0.20-M acetic acid, CH3COOH, which of these would form a buffer? 0.10 mol NaCH3COO 0.10 mol NaOH 0.10 mol HCl 0.30 mol NaOH Explain your answers.

Ammonia gas is bubbled into 275 mL of water to make an aqueous solution of ammonia. To prepare a buffer with a pH of 9.56, 15.0 g of NH4Cl are added. How many liters of NH3; at 25C and 0.981 atm should be used to prepare the buffer? Assume no volume changes and ignore the vapor pressure of water.

A buffer is prepared by dissolving 0.062 mol of sodium fluoride in 127 mL of 0.0399 M hydrofluoric acid. Assume no volume change after NaF is added. Calculate the pH of this buffer.

Consider the titration of butyric acid (HBut) with sodium hydroxide. In an experiment, 50.00 mL of 0.350 M butyric acid is titrated with 0.225 M NaOH. Ka HBut=1.5105. (a) Write a balanced net ionic equation for the reaction that takes place during titration. (b) What are the species present at the equivalence point? (c) What volume of sodium hydroxide is required to reach the equivalence point? (d) What is the pH of the solution before any NaOH is added? (e) What is the pH of the solution halfway to the equivalence point? (f) What is the pH of the solution at the equivalence point?

A solution is prepared by dissolving 0.350 g of benzoic acid, HC7H5O2, in water to make 100.0 mL of solution. A 30.00-mL sample of the solution is titrated with 0.272 M KOH. Calculate the pH of the solution (a) before titration. (b) halfway to the equivalence point. (c) at the equivalence point.