CHEM 162 2010 EXAM II Chapter 15 2 ndHalf Applic Of Acid Base Equilibria

Chem 162 2010 exam ii chapter 15 2 ndhalf applic of

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Addition of a weak base will react with the HA, resulting in a very small increase in pH. CHEM 162-2010 EXAM II Chapter 15 – 2 nd Half - 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 10-9 3 2 2 N CHEM 162-2009 FINAL EXAM
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8 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 W HA + OH - ĺ H 2 O + A - Initial 0.20 0.10 0 Change -0.10 -0.10 +0.10 Equilibrium 0.10 0 0.10 X HA + OH - ĺ H 2 O + A - Initial 0.10 0.20 0 Change -0.10 -0.10 +0.10 Equilibrium 0 0.10 0.10 Y NH 3 + H 3 O + ĺ NH 4 + + H 2 O Initial 0.20 0.10 0 Change -0.10 -0.10 +0.10 Equilibrium 0.10 0 0.10 Z NH 3 + H 3 O + ĺ NH 4 + + H 2 O Initial 0.10 0.20 0 Change -0.10 -0.10 +0.10 Equilibrium 0 0.10 0.10 W & Y are buffers. B
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9 11 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? 3 3 3 Assume everything is in a 1 L solution. A. NH 3 + H 3 O + ĺ NH 4 + + H 2 O NH 3 + H 3 O + ĺ NH 4 + + H 2 O 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 is a buffer. B. NH 4 + + NH 3 ĺ NR 0.2M of a conjugate acid & 0.4M of its base is a buffer. C. HBrO + OH - ĺ BrO - + H 2 O HBrO + OH - ĺ BrO - + H 2 O 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 is a buffer. D. HBrO + BrO - ĺ NR 0.2M of a weak acid & 0.1M of its conjugate base is a buffer E. NH 3 + OH - ĺ NR A weak base & a strong base is not a buffer. Chem 162-2008 Exam II + Answers
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10 Chapter 15B Applic. of Acid & Base Equilibria (Buffers & Titrations) Buffer concepts Definition of buffers; relationship between pH and pK a
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