Taylor Walsh Shiv Patel Emily Penn Philip Adejumo Chapter 17-4

 Be able to read a titration curve  Understand how titrations work  Perform titration calculations

 Equivalence point- the point at which stoichiometrically equivalent quantities of acids and bases have been brought together idbaseeqia/phcurves.html

 Titration- when a solution containing a known concentration of base is slowly added to an acid (or vice versa)  Titration enables us to find the equivalence point of the acid-base solution b/techniques/graphics/titration/titr ation6.gif

 A titration curve is a graph of the pH as a function of the volume of the added acid or base  There are 3 types of titrations with distinct titration curves:  Strong acid-strong base  Weak acid-strong base  Polyprotic acid-strong base

Equivalence Point Rapid Rise Portion Initial pH Final pH ed/titration/graphics/titration-strong-acid-35ml.gif

1. The initial pH a. The initial pH is a purely acidic solution 2. Between the initial pH and the equivalence point  pH slowly rises at first, then more Rapidly when it gets close to the Equivalence point 3. The equivalence point 4. After the equivalence point Ex..100 M NaOH added to 50.0 mL of.100 M HCl atitration.JPG

1. First determine how many moles of H + were originally present and how many moles of OH - were added 2. Subtract the two values (moles) to calculate moles of H + There are more moles of H + than moles of OH -, so the resulting value will be moles of H + Ex. Calculate the pH when the following quantities of M NaOH solution have been added to 50.0 mL of M HCl solution

1. The initial pH  pH of the acid 2. Between the initial pH and the Equivalence point 3. The equivalence point 4. After the equivalence point

 The solution of the weak acid has a higher initial pH than a solution of a strong acid of the same concentration  The pH change at the rapid-rise portion of the curve is smaller for the weak acid than it is for the strong acid  The pH at the equivalence point is above 7.00 for the weak acid-strong base titration  Equivalence point for strong acid-strong base is always at 7.00 pH

 Calculate [HX] and [X - ] after reaction  Use [HX], [X - ], and K a to calculate  Use [H + ] to calculate pH Ex: Calculate the pH of the solution formed when 45.0 mL of M NaOH is added to 50.0 mL of M HC2H3O2, (Ka = 1.8 x )

Before rxn0.0 mol HC 2 H 3 O 2 (aq) + OH - C 2 H 3 O 2 - (aq) After rxn0.0 mol

 Calculate the pH at the equivalence point in the titration of 50.0 mL of M HC2H3O2 with M NaOH

Calculate the pH at the equivalence point in the titration of 50.0 mL of M HC2H3O2 with M NaOH

 When weak acids contain more than one ionizable H atom (H 3 PO 3 )  Neutralization occurs in a series of steps H 3 PO 3 H 2 PO 3 - HPO eriments/images/titration_curve.jpg