At temperature 25°C, 0.02 M hydrazine, N2H4 solution is 0.69% ionised. Calculate the i. Concentration of OH- ion ii. ionisation constant, Kb

Using your knowledge of buffer systems , calculate the pH of blood with its carbonic acid buffer system.  The solution was made by dissolving 0.0036 mol of H2CO3 and 0.036 mol of HCO3- in 1.5 liters of water.(Please assume the total volume for the solution is 1.5 L; note: Ka = 4.3 x 10-7.) (Express your answer with 3 sig. figs.)

10. One characteristic of blood that we rarely give a thought to is its pH. The pH of blood must be held remarkably constant, varying only by a few hundredths of a pH unit from 7.36 to 7.40.  Blood pH is kept constant primarily through the buffering action of the bicarbonate ion, HCO3-, and dissolved carbon dioxide, commonly represented as H2CO3. The second ionization is negligible in blood so that H2CO3 can be treated as a monoprotic acid.  A) If the Ka1 for H2CO3 is 4.2 * 10-7, what ratio of HCO3- to H2CO3 is necessary to produce a buffer of pH 7.40? B) What is the pH of a buffer that is 1.0 M NaHCO3 and 1.0 M H2CO3? C) If you have 1.00 L of the buffer described above (1.0 M NaHCO3 and 1.0 M H2CO3) and 10.0 mL of 0.100 M HCl is added to it, what is the new pH? D) Just to prove that the buffer helps minimize changes in pH, calculate the pH of a solution prepared by adding 10.0 mL of 0.1 M HCl to 1.00 L of pure water.

33)

Solution X is a 400 mL benzoate/benzoic acid buffer solution with a pH of 3.49. If the concentration of benzoic acid present in solution X is 0.3 mol L–1, calculate the concentration of sodium benzoate (in mol L–1) present in solution X at 25 °C. The Ka of benzoic acid is 6.5E-5.

A second titration is performed using the same 0.250 M NaOH in a buret. This time 25.0mL of an H2SO4 soln is titrated. At the endpoint 47.8 mL of NaOH has been added to theH2SO4 soln. What is the molarity of the H2SO4?

A 1.43 L buffer solution consists of 0.103 M butanoic acid and 0.300 M sodium butanoate. Calculate the pH of the solution following the addition of 0.069 moles of NaOH. Assume that any contribution of the NaOH to the volume of the solution is negligible. The K, of butanoic acid is 1.52 x 10-5. pH =