Calculate the pH of an aqueous solution of 0.1 M Na2SO4 at 25oC. Note 1: the pH of pure water is 7 and that Na2SO4 is neither an acid nor a base. Note 2: use concentration only (not activity) in your calculation. Kw at 25oC = 1.0 X 10–14.

At 40 °C, Kw = 2.92 × 10‒14. At 50 °C, a solution with pOH = 7.00, has a pH of ____________. Group of answer choices:   7.00 and is neutral. 7.00 and is slightly basic. 6.53 and is slightly basic. 6.53 and is slightly acidic.

1. A 0.0250 M Ca(X)₂ has a pH of 8.049. Ca(X)₂ is composed of a Ca²+ cation and an unknown anion X, which undergoes hydrolysis. A. Write the balanced dissociation reaction of Ca(X)2 into its ions. Write your answer on your solution sheet B. Write the balanced hydrolysis reaction of the unknown anion, X. Write your answer on your solution sheet C. Calculate the K₁, or K, of X. D. Given the following K, values of different weak acids, determine the identity of X. Weak acids Ka HIO 2.00 x 10-11 HCN 6.17 x 10-10 CH₂COOH 1.80 x 105 HNO2 4.00 x 104

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.

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 monoprotic weak acid, HA, dissociates in water according to the reaction HA(aq) + H,O(1) =H,0*(aq) + A¯(aq) The equilibrium concentrations of the reactants and products are [HA] = 0.140 M, [H,O*] = 4.00 × 10-4 M, and [A = 4.00 x 10-4 M. Calculate the Ka value for the acid HA. K =

Calculate the pH at 25 °C of a 0.44M solution of potassium butanoate (KC,H,CO,). Note that butanoic acid (HC,H,CO,) is a weak acid with a p K, of 4.82. Round your answer to 1 decimal place. pH = 0

Calculate the pH of a solution of 0.25M NaclO(ag). The Ka of HCIO is 2.9 x 10-8.

Part A Water ionizes by the equation =H+(aq) + OH (ag) The extent of the reaction is small in pure water and dilute aqueous solutions. This reaction creates the following relationship between [H*] and [OH ]: What is the H† concentration for an aqueous solution with pOH = 2.73 at 25 °C? Express your answer to two significant figures and include the appropriate units. Kw = [H*][OH¯] • View Available Hint(s) Keep in mind that, like all equilibrium constants, the value of Kw changes with temperature. ? [H*] = Value Units

Each row of the table below describes an aqueous solution at 25 °C. The second column of the table shows the initial components of the solution. • Use the checkboxes in the third column to explain the type of the initial solution. The fourth column describes a change in the solution. • Use the fifth column to predict how the change in the solution will change its pH. solution initial components A B C D H₂O H₂O, NaOH H₂O H₂O, NaOH initial type (check all that apply) acidic basic neutral acidic basic neutral acidic basic neutral acidic basic оо 00 neutral change add HCl add Na Br add K Cl add H Br effect of change on pH (check one) pH higher pH lower ο ο1ο ο ο ο ο ο pH the same pH higher pH lower pH the same pH higher pH lower pH the same pH higher pH lower pH the same