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Addition of a weak acid will react with the A-, resulting in a very small decrease in pH. E. CHEM 162-2010 EXAM II Chapter 15 – 2ndHalf - Applic. Of Acid & Base Equilibria (Buffers & Titrations) Buffer concepts 12. Which of the following combinations would make a buffer closest to pH 9.0? HClO2Ka= 1.1 x 10-2NH3Kb= 1.8 x 10-5HNO2Ka= 7.2 x 10-4C5H5N Kb= 1.5 x 10-922N
8CHEM 162-2009 FINAL EXAM CHAPTER 15B - APPLIC. OF ACID & BASE EQUILIBRIA BUFFER CONCEPTS 50. Which of the following mixtures willresult in a buffer? W. 0.20 mol CH3COOH + 0.10 mol NaOH in 1.00 L solution X. 0.20 mol NaOH + 0.10 mol CH3COOH in 1.00 L solution Y. 0.20 mol NH3+ 0.10 mol HCl in 1.00 L solution Z. 0.20 mol HCl + 0.10 mol NH3in 1.00 L solution A-0 A-0 2O 0 2O 0 B
911 Chem 162-2008 Final Exam + Answers Chapter 15B- Acids, Bases and Acid-Base Equilibria Buffer concepts Which of the following mixtures does notresult in a buffer? 333Assume everything is in a 1 L solution. A. NH3+ H3O+ĺNH4++ H2O NH3+ H3O+ĺNH4++ H2O Initial 0.3M 0.1M 0 0 Change -0.1 -0.1 +0.1 +0.1 Equilibrium 0.2M 0.1M 0.2M of a base & 0.1M of its conjugate acid isa buffer. B. NH4++ NH3ĺNR 0.2M of a conjugate acid & 0.4M of its base isa buffer. C. HBrO + OH-ĺBrO-+ H2O HBrO + OH- ĺBrO-+ H2O Initial 0.2M 0.1M 0 0 Change -0.1 -0.1 +0.1 +0.1 Equilibrium 0.1M 0M 0.1M 0.1M 0.1M weak acid & 0.1M conjugate base isa buffer. D. HBrO + BrO-ĺNR 0.2M of a weak acid & 0.1M of its conjugate base isa buffer E. NH3+ OH-ĺNR A weak base & a strong base is nota buffer.
10Chem 162-2008 Exam II + Answers Chapter 15B Applic. of Acid & Base Equilibria (Buffers & Titrations) Buffer concepts Definition of buffers; relationship between pH and pKa