Chapter 2 Student Lab Notes - Acids, Bases, and pH PDF
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SLAC / San Antonio College
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This document provides student lab notes on the topic of acids, bases, and pH. The notes cover learning objectives, pH, solutions, acids, bases, neutralization, and buffers. It also includes information specifically about the carbonic acid-bicarbonate buffer system.
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Chapter 2 Atoms, Ions, and Molecules Acids, Bases, and pH Learning Objectives Define pH and differentiate between acidity and basic solutions Compare and contrast the characteristics of acids and bases Describe how buffers maintain blood pH in the carbonic acid-bicarbonate buffer syste...
Chapter 2 Atoms, Ions, and Molecules Acids, Bases, and pH Learning Objectives Define pH and differentiate between acidity and basic solutions Compare and contrast the characteristics of acids and bases Describe how buffers maintain blood pH in the carbonic acid-bicarbonate buffer system (SLO A, C) pH pH is a measure of H+ Relative amount of H+ in a solution Range between 0 and 14 pH and H+ concentration are inversely related As H+ concentration increases, pH decreases As H+ concentration decreases, pH increases pH and Solutions Neutral solutions (pH of 7) have equal concentrations of H+ and OH− Acidic solutions (pH < 7) have greater H+ than OH− Basic solutions (pH > 7) have greater OH− than H+ Moving from one increment to next is a 10-fold change For example, a pH of 6 has 10 times greater concentration of H+ than pure water (pH 7) Acids Proton donor Increases concentration of free H+ More dissociation of H+ with stronger acids For example, HCl in the stomach Less dissociation of H+ with weaker acids For example, carbonic acid in the blood Bases Proton acceptor Decreases concentration of free H+ More absorption of H+ with stronger bases For example, ammonia and bleach Less absorption of H+ with weaker bases For example, bicarbonate in blood and in secretions released into small intestine Neutralization When an acidic or basic solution is returned to neutral (pH 7) Acids neutralized by adding base For example, medications to neutralize stomach acid must contain a base Bases neutralized by adding acid Buffers Help prevent pH changes if excess acid or base is added Act to accept H+ from excess acid or donate H+ to neutralize base Carbonic acid (weak acid) and bicarbonate (weak base) buffer blood pH Both help maintain blood pH in a critical range (7.35 to 7.45) Low blood pH = acidosis High blood pH = alkalosis Carbonic Acid- Bicarbonate Buffer System Lungs regulate CO2 Kidneys regulate bicarbonate
