formic acid (HCOOH) and sodium formate (NaCOOH). The Ka for formic acid is 1.8 x 10-4. The simultaneous equilibrium reaction is as shown below. Calculate the pH and the buffer capacity of the solution.  HCOOH (aq) + H2O (l) ⇋ H3O+ (aq) + HCOO- (aq)

A chemist titrates 100.0 mL of a 0.0714M nitrous acid (HNO,) solution with 0.3683M KOH solution at 25 °C. Calculate the pH at equivalence. The p K, of nitrous acid is 3.35. Round your answer to 2 decimal places. Note for advanced students: you may assume the total volume of the solution equals the initial volume plus the volume of KOH solution added. pH = |

(a) Using the expression Ka=[H+][A−]/[HA], explain how to determine which solution has the lower pH, 0.10MHF(aq) or 0.10MHC2H3O2(aq). Do not perform any numerical calculations. (b) Which solution has a higher percent ionization of the acid, a 0.10M solution of HC2H3O2(aq) or a 0.010M solution of HC2H3O2(aq) ? Justify your answer including the calculation of percent ionization for each solution.

Calculate the change in pH when 3.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH₂ (aq) and 0.100 M in NH₂Cl(aq). Consult the table of ionization constants as needed. ΔΡΗ = Calculate the change in pH when 3.00 mL of 0.100 M NaOH is added to the original buffer solution. ApH =

B represents an acid-base indicator and behaves like a base. Its dissociation equilibrium in an aqueous solution can be written as: B(ac) + H2O(l) <-> +BH(ac) + OH(ac) If B (ac) is yellow +BH is red. Using Le Châtelier's principle, predict the color of the indicator by adding a few drops of the indicator to an aqueous solution of HCl and an aqueous solution of NaOH. Write the corresponding chemical reactions.

You prepare a MOPS buffer by adding 0.10 mol MOPS to water then adding 0.040 molNaOH and diluting to a final volume of 500. mL.Calculate the pH of this buffer   C7H14NO3SOH (aq) + NaOH (aq) → C7H14NO3SO− (aq) + Na+ (aq) + H2O (l)

2. Dr. Dahm has prepared 250 mL of a acetate buffer which contains 0.1 mol of acetic acid (CH₂COOH) and 0.15 moles of acetate (CH₂COO). Determine the initial pH. If he then adds 0.025 moles of H* calculate the new pH. Ka = 1.8 × 10³ CH₂COOH(aq) + H₂O CH₂COO (aq) + HO (aq) 3. Dr. Dahm makes a second acetate buffer exactly the same way as in #2, but he then adds 15 mL of 0.50 M NaOH calculate the new pH.

A buffer is made by adding 0.18 mol/L of sodium propanoate (NaPr) to 0.12 mol/L solution of propanoic acid (HPr, K«= 1.3 x 10-5). Assume the volume of the solution to be 1.0 L. a) Write the chemical equation for the acid hydrolysis reaction. | b) What is the acid-base conjugate pair that governs the pH of the buffer? c) Calculate the pH of the buffer. Be sure to justify and validate any approximations used.

Calculate the pH for the complete titration of 100.0 mL of 0.122 M hydrazine, H2NNH2, with 0.200 M nitric acid.  The Kb for hydrazine is 3.00x10-6.   H2NNH2(aq) +HNO3(aq) ⟶ [H2NNH3]+1(aq) + NO3-1(aq) 1. 4.80 2. 9.60 3. 4.70 4. 9.39 5. 3.22 6. 3.32

A buffer solution is made that is 0.492 M in H2S and 0.492 M in KHS. If Ka1 for H2S is 1.00x10^-7, what is the pH of the buffer solution? pH =  Write the net ionic equation for the reaction that occurs when 0.135 mol NaOH is added to 1.00 L of the buffer solution. (Use the lowest possible coefficients. Omit states of matter.)   +       +