7. Write the charge balance for the following solutions and list the equations that would have to be solved to determine the equilibrium solution composition. (a) 103 M benzoic acid (b) 10-3 M Na₂S (c) 103 M (NH4)2CO3 (d) 10-3M (NH4)2CO3 plus 5 × 10-3 M (NH4)3PO4 plus 10-3 M CaCO3

Given the following hydrolysis constants, which of the salts has the weakest parent ACID? K₂ or K, for salt 3.3 x 10-7 5.6 x 10-10 5.6 x 10-10 5.0 x 10-6 (A) (B) (C) (D) SALT NaClO2 NH4NO3 C₂H302 C₂H5NHBr NaCN A E B 2.5 x 10-5.

Determine the pH during the titration of 67.3 mL of 0.459 M hypochlorous acid (K 3.5x108) by 0.459 M NaOH at the following points. (Assume the titration is done at 25 °C.) (a) Before the addition of any NaOH X (b) After the addition of 17.0 mL of NaOH X t (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point x pt (e) After the addition of 101 mL of NaOH 12.95 pt pt X

In the titration of 60.0 mL of 1.0 M methylamine, CH3NH₂ (K₁ = 4.4 x 10-4), with 0.50 M HCI, calculate the pH under the following conditions. (a) after 0.00 mL of 0.50 M HCI has been added 4.0 (b) after 20.0 mL of 0.50 M HCI has been added 4.0✔ (c) after 60.0 mL of 0.50 M HCI has been added 4.0✔ (d) at the stoichiometric point 4.0✔ (e) after 200.00 mL of 0.50 M HCI has been added 4.0