Determine whether or not the mixing of each pair of solutions results in a buffer. b. 125.0 mL of 0.14 M HF; 195.0 mL of 0.070 M NaOH
Ch.18 - Aqueous Ionic Equilibrium
Chapter 18, Problem 56b
Determine whether or not the mixing of each pair of solutions results in a buffer. b.155.0 mL of 0.15 M NH3 ; 155.0 mL of 0.10 M HCl
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Identify the components needed for a buffer solution: a weak base and its conjugate acid, or a weak acid and its conjugate base.
Recognize that NH3 (ammonia) is a weak base and HCl (hydrochloric acid) is a strong acid.
Calculate the moles of NH3 using the formula: moles = concentration (M) \times volume (L).
Calculate the moles of HCl using the formula: moles = concentration (M) \times volume (L).
Determine if the amount of HCl is enough to partially neutralize NH3, forming NH4^+ (the conjugate acid), without completely neutralizing it, which would result in a buffer solution.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Buffer Solutions
A buffer solution is a system that resists changes in pH upon the addition of small amounts of acid or base. It typically consists of a weak acid and its conjugate base or a weak base and its conjugate acid. Buffers are crucial in maintaining stable pH levels in various chemical and biological processes.
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Buffer Solutions
Weak Bases and Their Conjugate Acids
Weak bases, like ammonia (NH3), partially ionize in solution to form hydroxide ions (OH-) and their conjugate acids. When mixed with a strong acid, such as hydrochloric acid (HCl), the weak base can react with the acid to form its conjugate acid, which is essential for buffer formation. Understanding this equilibrium is key to determining buffer capacity.
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Conjugate Acid-Base Relationships
pH and Acid-Base Reactions
pH is a measure of the acidity or basicity of a solution, defined as the negative logarithm of the hydrogen ion concentration. In acid-base reactions, the pH changes based on the concentrations of acids and bases present. Analyzing the resulting pH after mixing solutions helps determine if a buffer is formed, as buffers maintain a relatively constant pH.
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pH of Strong Acids and Bases
Related Practice
Textbook Question
Textbook Question
Determine whether or not the mixing of each pair of solutions results in a buffer. c. 55.0 mL of 0.15 M HF; 85.0 mL of 0.10 M NaF
Textbook Question
Determine whether or not the mixing of each pair of solutions results in a buffer. a. 155.0 mL of 0.15 M NH3 ; 175.0 mL of 0.17 M HCl
Textbook Question
Determine whether or not the mixing of each pair of solutions results in a buffer. c. 225.0 mL of 0.10 M NH3 ; 250.0 mL of 0.15 M NH4Cl
Textbook Question
Determine whether or not the mixing of each pair of solutions results in a buffer. d. 150.0 mL of 0.15 M HCl; 135.0 mL of 0.25 M NaOH
Textbook Question
Blood is buffered by carbonic acid and the bicarbonate ion. Normal blood plasma is 0.024 M in HCO3- and 0.0012 M H2CO3 (pKa1 for H2CO3 at body temperature is 6.1).
a. What is the pH of blood plasma?
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