A weak acid, HA, has pKa=6.2. If a solution of NaA (aq) is prepared, what does the pH of the solution need to be adjusted to in order to achieve the following ratios of deprotonated species? A) [A-]/[HA]=0.01 B) [A-]/[HA]=1

The pKa of a particular weak acid is 4.85. What is the pH of the weak acid solution when exactly half of the acid is neutralized?

A sample of solid sodium hydrogen phosphate is dissolved in water and allowed to come to equilibrium at 25 °C. NaH PO (aq) + H»O(1) = H2PO (aq) + NAOH(aq) 4 4 The OH concentration is measured and at equilibirum OH = 3.54 × 10 13 M. What is the pH of the solution? Type your answer...

Write the equilibrium constant expression for this reaction: →>> H3PO4(aq) 3 H(aq) +PO(aq)

Aluminum hydroxide dissolves in strong acid by the following reaction. Al(OH)3(s) + 3 H3O+(aq)  Al3+ (aq) + 6 H2O(l) (a) What is the equilibrium constant expression for the reaction? (b) Use the following equilibrium constants to calculate the value of K for the above reaction. H3O+(aq) + OH −(aq)  2 H2O(l) K1 = 5.6  x1015 Al(OH)3(s)  Al3+(aq) + 3 OH −(aq) K2 = 1.9  x10-33

You are on one of Saturn's many moons and discover a substance, Y2O that undergoes autoionization just like water on Earth.  Y2O + Y2O  ⇌ Y3O+ + OY– Through a series of experiments, you determine the equilibrium constant (Keq) for this autoionization reaction at various temperatures. The value of Keq at 28.7ºC is 7.6 x 10-14. What is the pY of the pure substance at this temperature? Report your answer to the hundreths place

(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.

A 1.00 L solution contains 0.383 M HA (K₂ = 4.52 · 10−4) and 0.790 M NaA. What is the pH of this solution? What is the pH if 0.121 L of 0.178 M KOH is added to the solution be? What is the pH if 0.242 L of 0.178 M KOH is added to the solution be? 3.65

43.  A buffer is prepared using acetic acid, CH3COOH, (a weak acid, pKa = 4.75) and sodium acetate, CH3COONa (which provides acetate ions, the conjugate base), according to the following proportions:   Volume of CH3COOH(aq):   125.0 mL Concentration of CH3COOH(aq):  1.263 M   Volume of CH3COONa(aq):  106.0 mL Concentration of CH3COONa(aq):  1.279 M   Determine the volume of 6.00 M HCl required to change the pH of this buffer by one pH unit.       18.15 mL     36.30 mL     21.87 mL     19.30 mL     43.73 mL

Human blood has a pH of approximately 7.4 due to the carbonic acid/bicarbonate ion (H2CO3/HCO3−) buffer system. Any pH changes below 6.8 or above 7.8 can lead to death! Carbonic acid dissociates to form water and carbon dioxide in the equilibrium shown below. This process is crucial in respiration. H2CO3 (aq) ⇋ CO2 (g) + H2O pKa1 = 2.77 Carbonic acid dissociates in water to form the bicarbonate ion and the hydroxonium ion by the following equilibrium reaction:H2CO3 (aq) + H2O ⇋ H3O(aq)+ + HCO3− pKa2 = 3.70    (i) If there is a 25% increase in carbonic acid levels as per pKa1, explain how the body would deal with this change.