A buffer is prepared using lactic acid (HLac) and sodium lactate (NaLac). 0.300 dm3 of the 0.500 mol·dm–3 HLac solution is mixed with 0.300 dm3 of the 0.300 mol·dm–3 NaLac solution to prepare the buffer. Ka for lactic acid (HLac) is 1.4 x 10–4   Calculate the pH of the sodium lactate solution before it is mixed with the HLac to form the buffer.

Determine the pH at the equivalence (stoichiometric) point in the titration of 48.38 mL of 0.171 M HCN (aq) with 0.135 M NaOH(aq). The Ka of HCN is 4.9 * 10^-10.

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

Calculate the change in pH when 6.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). Consult the table of ionization constants as needed.   ΔpH=?     Calculate the change in pH when 6.00 mL of 0.100 M NaOH is added to the original buffer solution.   ΔpH=?

The pH of an aqueous solution of 0.400 M hydrocyanic acid, (Ka (HCN) = 4.00 × 10-10) is

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.

Estimate the calcium concentration (in ppm by mass) in a groundwater sample, which has a pH of 5.63. Assume that the groundwater at this location is saturated with CO2 at a partial pressure of 0.185 atm. The atomic weight of calcium is 40.1 g/mol.

5) Find the concentration of H30*(aq) in a 1.75 M solution of lactic acid, HC3H5O3, at 25°C. Ka= 1.38 x 10*. 6) Write the equilibrium expression for the ionization of HOI, and calculate the concentration of HOI(aq) in solution if [H3O*]=2.3 x 10° M and pKa = 10.7 at 25°C.

7.7 g of citric acid (MM = 192.1 g/mol) can be titrated with NaOH according to the following balanced chemical equation.           H3C6H5O7  (aq) + NaOH(aq) → H2O(l) + Na H2C6H5O7(aq) what would the curve for the titration of the neutralization of the three hydrogens of this acid with NaOH look like?

1) Calculate the pH of a solution prepared by dissolving 1.90 g of sodium acetate, CH,COONA, in 64.0 mL of 0.15 Macetic acid, CH;COOH(ag). Assume the volume change upon dissolving the sodium acetate is negligible. K, of CHCOOH is 1.75 x 105. Calculate the amount of heat released or absorbed by the following substance: 90.23g of iron, AT= 86°C Calculate the amount of heat released or absorbed by the following substance: 7.45g of silicon, final temperature = -10°C, initial temperature = 25°C