What is the pH of a 0.1 M NaF solution? Ka for HF…


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What is the pH of a 0.1 M NaF solution? Ka for HF is 7.0 x 10-4. a. 4.4 b. 5.9 c. 8.1 d. 9.2 e. 10.3 Save Answer 2. (Points: 1) Propanoic acid (CH3CH2COOH) has a Ka of 1.34 × 10-5. A 25.00 mL sample of 0.1000 M propanoic acid (in flask) is titrated with 0.1000 M NaOH solution, added from a buret. Carry out the calculations of the quantities indicated below, & put your answers in the boxes below. 1. The pH after 0.00 mL of NaOH are added. 2. The pH after 15.00 mL of NaOH are added. 3. The hydroxide ion concentration after 26.00 mL of NaOH are added. 1. 2. 3. Save Answer 3. (Points: 1) A 10.0-mL sample of 0.75 M CH3CH2COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? Ka = 1.3 × 10-5 1. Save Answer 4. (Points: 1) A 25.0-mL sample of 0.130 M HCl is mixed with 15.0 mL of 0.240 M of NaOH. The pH of the resulting solution will be nearest [Hint: use stoichiometry to solve this problem. Don’t forget to recalculate the concentration using the TOTAL volume of the mixture] a. 2.1 b. 7 c. 11.9 d. 13 Save Answer 5. (Points: 1) A diprotic acid H2A has Ka1 = 1 × 10-4 and Ka2 = 1 × 10-8. The corresponding base A2- is titrated with aqueous HCl, both solutions being 0.1 mol L-1. Which one of the following diagrams best represents the titration curve that will be observed? a. b. c. d. e. Save Answer 6. (Points: 1) Which of the following compounds is a strong electrolyte? a. HNO3 b. HNO2 c. NH3 d. H2O e. HF Save Answer 7. (Points: 1) When aqueous solutions of Ba(OH)2 and H2SO4 are mixed, a reaction occurs. What ions, if any, are the spectator ions in this reaction? a. Ba2+ and OH- b. H+ and SO42- c. Ba2+ and SO42- d. H+ and OH- e. There are no spectator ions since all of them react. Save Answer 8. (Points: 1) Which of the following pairs of materials will make the best buffer at pH = 6.8? a. NaHCO3/H2CO3 Ka = 4.3 x 10-7 b. KCN/HCN Ka = 4.9 x 10-10 c. Na lactate/lactic acid Ka = 1.4 x 10-4 d. NaAcetate/Acetic Acid Ka = 1.8×10-5 e. NH4+/NH3 Ka = 5.89 x 10-10 Save Answer 9. (Points: 1) Calculate the pH of a solution that contains 6.1 g/L of benzoic acid, C6H5COOH. The Ka for benzoic acid is 6.3×10-5 1. Save Answer 10. (Points: 1) For the reaction A+B <--> C, K = 13.0 If 0.1 mmole of A and 0.3 mmole of B are mixed and diluted to 10.0 mL, calculate the equilibrium concentrationsin molarity of A, B, & C. Put A in Box 1, B in Box 2, and C in Box 3. 1. 2. 3. Save Answer 11. (Points: 1) Calculate the [H+] for a 0.10 M solution of dichloroacetic acid at equilibrium. Hint: the pKa = 1.26 1. Save Answer 12. (Points: 1) Calculate how many moles of H+ or OH- must be added per liter of solution to change its pH from 3.25 to 3.65. Assume a negligable volume change. Put this answer in Box 1. In Box 2, indicate which you would add, H+ or OH-. 1. 2. Save Answe

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