Titration. Titration of a Strong Acid by a Strong Base Consider what happens to the pH of 25 mL of 0.2 M HCl as it is titrated with 25 mL of 0.2 M NaOH.

Slides:

Advertisements

Similar presentations

III. Titration (p. 493 – 503) Ch. 15 & 16 – Acids & Bases.

Advertisements

Entry Task: Feb 12th Tuesday

Acid-Base Titrations progressive addition of one reactant to another in measured volumes until an endpoint is reached. equivalence point (mL) is when.

Slide 1 of 45  Worked Examples Follow:. Slide 2 of 45.

Acid-Base Stoichiometry

Chemistry Notes: Titrations Chemistry  A titration is a lab procedure which uses a solution of known concentration to determine the concentration.

Neutralization Chapter 21.

Solution Stoichiometry

Measuring pH Indicators Titrations

Procedure for calculating pH of a titration Volume of titrant needed is based on amount of analyte.

ANALYTICAL CHEMISTRY CHEM 3811 CHAPTER 10 DR. AUGUSTINE OFORI AGYEMAN Assistant professor of chemistry Department of natural sciences Clayton state university.

Topic 1.5 Titrations. Titrations In a titration a solution of accurately known concentration is added gradually added to another solution of unknown concentration.

Strong Acid-Base Titrations Chapter 17. Neutralization Reactions Review Generally, when solutions of an acid and a base are combined, the products are.

There are several ways to test pH – Blue litmus paper red = acid – Red litmus paper blue = basic – pH paper multi-colored – pH meter 7 is neutral, 7 base.

Acid-Base Titrations.

THE MATHEMATICS IN A TITRATION CURVE (WITH A LITTLE BASE 10 AND LOGARITHM ARITHMATIC ADDED)

Titrations Titrations A. Titrations – is an experimental procedure in which a standard solution is used to determine the concentration of an unknown.

© University of South Carolina Board of Trustees Chapt. 16 More Acids and Bases Sec. 2 Titration: Strong Acid + Strong Base.

Aqueous Equilibria Bicarbonate buffer system. Aqueous Equilibria Buffers: What are they????? Solutions of a weak acid and its conjugate Or a weak base/conjugate.

Titration Calculations. An example of titration problem: I have a mL sample of a strong acid at an unknown concentration. After adding mL.

1 And Acid/Base dilution Mr. Shields Regents Chemistry U15 L05.

ACIDS AND BASES Acid Base Titration A very accurate method to measure concentration. Acid + Base  Salt + Water H + + OH -  H 2 O Moles H + = Moles.

Updates Assignment 06 is due Mon., March 12 (in class) Midterm 2 is Thurs., March 15 and will cover Chapters 16 & 17 –Huggins 10, 7-8pm –For conflicts:

(equimolar amounts of acid and base have reacted)

Section 16.3 Titrations and Buffers 1.To know how to neutralize acids and bases (titration) Learning Goal.

19.4 Neutralization Reactions > 1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Chemists use acid-base reactions to determine.

Acid Base Titrations AP Chemistry Chapter 15. Titration Titrations are used to determine the amount of acid or base in a solution Titrant: the solution.

19.4 Neutralization Reactions > 1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Chemists use acid-base reactions to determine.

Titration and pH Curves..   A titration curve is a plot of pH vs. volume of added titrant.

Addition of Strong Acids or Bases to Buffers -- Reactions between strong acids/bases and weak bases/acids proceed to completion. -- We assume that the.

Aspects of Aqueous Equilibria. Aspects of Aqueous Equilibria: The Common Ion Effect Recall that salts like sodium acetate are strong electrolytes NaC.

WOLPA/AP CHEMISTRY/CDO Chapter 18 Acid-Base Equilibria.

1 Acid-Ionization Titration Curves  An acid-base titration curve is a plot of the pH of a solution of acid (or base) against the volume of added base.

Acid - Base Titration. What is a Titration? A titration is a procedure used in chemistry to determine the concentration of an unknown acid or base. A.

8 - 1 Titrations An acid-base titration is a volumetric analysis in which a solution of one reactant (acid or base) is gradually added to a solution of.

Aqueous Equilibria Unit 19 Acid Base Equilibria: Titrations Dr. Jorge L. Alonso Miami-Dade College – Kendall Campus Miami, FL CHM 1046: General Chemistry.

Why do Titration Curves Look Like THAT ???? 1/4/20161.

bjects/3312/ /blb1703.html.

Unit 6 - Chpt 15 - Acid/Base Equilibria Common Ion Effect Buffers / Buffer Capacity Titration / pH curves Acid / Base Indicators HW set1: Chpt 15 - pg.

Acid-Base Titrations Section Introduction Definition: – In an acid-base titration, a solution containing a known concentration of a base is slowly.

Aqueous Equilibria The Common-Ion Effect Consider a solution of acetic acid: NaC 2 H 3 O 2 Le Châtelier says the equilibrium will shift to the ______.

Additional Aspects of Aqueous Equilibria. Roundtable problems P.757: 3, 6, 12, 14, 18, 24, 30, 38, 44, 50, 54, 56, 58, 64, 68, 70, 72, 103.

Loose Ends from Bell Work An acidic solution makes the color of pH paper turn ___________________, while a basic solution makes the color of pH paper turn.

10.3Acid-Base Stoichiometry. Titration A method for determining the concentration of a solution by reacting a known volume of that solution with a solution.

NEUTRALIZATION, INDICATORS, AND TITRATIONS. NEUTRALIZATION REACTIONS So far we have only looked at acid and base reactions with water Ka and Kb reactions.

Buffer Example and Titration Calculations. pH Change to 1M Acetic Acid/1M Acetate Ion Soln. Moles H + Added 0 Moles OH - Added.

Kinds of Titrations. Titration of a Strong Acid With A Base As a strong base is titrated into a strong acid, there is just a slight increase in pH until.

Titration. Definition Process used to determine the strength of an unknown acid or base Can determine the unknown acid by adding to it a base of known.

PART A M C V C = M D _______ V D = (1.0 M)(5.0 mL) ___________________ (50.0 mL) = 0.10 M HC 2 H 3 O 2.

Obj. finish 17.2, ) The pH range is the range of pH values over which a buffer system works effectively. 2.) It is best to choose an acid with.

Acid-Base Titrations Calculations. – buret to hold the titrant – beaker to hold the analyte – pH meter to measure the pH.

POINT > Review acid-base neutralization POINT > Identify pH indicators and how they work POINT > Describe titration process.

Titration and pH Curves..   A titration curve is a plot of pH vs. volume of added titrant.

BUFFER – A solution of about equal amounts of a weak acid and its weak conjugate base A buffer is resistant to changes in pH because it can neutralize.

Buffer Effectiveness, Titrations, and pH Curves.

Main Idea: Titrations are an application of acid-base neutralization reactions that require the use of an indicator. 1 Titrations.

Titration A standard solution is used to determine the concentration of another solution.

Acid-Base Titrations End point and equivalence point

Titration and pH Curves.

Chemistry 19.4.

Neutralization.

Chemistry 19.4.

-5 M Review: 50 mL of 0.1 M carbonic acid, H2CO3, with an initial pH of 3.5, is titrated with 0.2 M lithium hydroxide, LiOH. What volume of.

Warm-Up Do not turn in pH practice!

Determining the pH and Titrations

17.3 Acid-Base Titrations.

Warm-Up Get out your pH Practice What is the pH of a solution that is made from 43.7 g of HClO4 in 4.70 L of solution?

Acid-Base Reactions.

Presentation transcript:

Titration

Titration of a Strong Acid by a Strong Base Consider what happens to the pH of 25 mL of 0.2 M HCl as it is titrated with 25 mL of 0.2 M NaOH. This result is shown in the diagram to the right. The diagram is referred to as a ___________________ _____________. As you add base, [H + ] ____________ and pH ___________ until what happens?

Ex #1:The following quantities of M NaOH have been added to 50.0 mL of M HCl. Calculate the pH of the resulting solutions. a mL b mL c mL d mL Titration of a Strong Acid by a Strong Base

a mL b mL c mL d mL Because the pH change for strong/strong titrations is large near the equivalence point, the indicator need not change color at exactly pH = 7. Phenolphthalein is often the choice for strong/strong titrations. Its color change occurs during a pH change of 8.3 to 10, but just a slight excess (a few drops) of the titrant will cause this change. Titration of a Strong Acid by a Strong Base Ex #1:The following quantities of M NaOH have been added to 50.0 mL of M HCl. Calculate the pH of the resulting solutions.

Titration of a Weak Acid with a Strong Base Calculating the pH of the weak acid depends on where you are in the titration process. HC 2 H 3 O 2 + Na + + OH -  Na + + C 2 H 3 O H 2 O Titration Process 1)Before the titration starts 2)Before the equivalence point is reached 3)At the equivalence point 4)After the equivalence point has been reached HC 2 H 3 O 2 NaOH Consider the titration of acetic acid with sodium hydroxide.

Titration of a Weak Acid with a Strong Base Titration Process 1)Before the titration starts HC 2 H 3 O 2 NaOH Consider the titration of acetic acid with sodium hydroxide. Initially, we just consider the acetic acid before any base is added. To calculate the pH, follow the same process as calculating the pH of a weak acid. Calculating the pH of the weak acid depends on where you are in the titration process. HC 2 H 3 O 2 ↔ C 2 H 3 O H 2 O

Titration of a Weak Acid with a Strong Base Titration Process 2) Before the equivalence point is reached HC 2 H 3 O 2 NaOH Consider the titration of acetic acid with sodium hydroxide. Think about what species are present so that we approach the problem from the correct perspective. The equation shows that since both HC 2 H 3 O 2 and C 2 H 3 O 2 -- are present, this becomes a _______ problem. Calculating the pH of the weak acid depends on where you are in the titration process. HC 2 H 3 O 2 ↔ C 2 H 3 O H 2 O

Titration of a Weak Acid with a Strong Base Titration Process 3) At the equivalence point HC 2 H 3 O 2 NaOH Consider the titration of acetic acid with sodium hydroxide. At the equivalence point, for a strong acid with a strong base, the pH = ______. This is not the case for a weak acid problem. Why? Calculating the pH of the weak acid depends on where you are in the titration process. HC 2 H 3 O 2 + Na + + OH -  Na + + C 2 H 3 O H 2 O

Titration of a Weak Acid with a Strong Base Titration Process 4)After the equivalence point has been reached HC 2 H 3 O 2 NaOH Consider the titration of acetic acid with sodium hydroxide. After the equivalence point has been reached, the additional OH -- has nothing left to react with so the pH is determined by __________________________________. Calculating the pH of the weak acid depends on where you are in the titration process.

Titration of a Weak Acid with a Strong Base Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH. Since the molarities are equal and the acid is monoprotic, we will need _______ mL of NaOH to reach the equivalence point. Why is it important to realize this before we begin the problem? 25

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? Initially, we just consider the acetic acid before any base is added. To calculate the pH, follow the same process as calculating the pH of a weak acid. Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R[HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I C -x+x E 0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔[H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Titration of a Weak Acid with a Strong Base 1) What is the pH before titration? HC 2 H 3 O 2 ↔ H + + C 2 H 3 O 2 - R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I0.200 C-x+x E0.2-xxx Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

2) What is the pH after mL of the base has been added? Titration of a Weak Acid with a Strong Base Think about what species are present so that we approach the problem from the correct perspective. The equation shows that since both HC 2 H 3 O 2 and C 2 H 3 O 2 -- are present, this becomes a _______ problem. HC 2 H 3 O 2 ↔ C 2 H 3 O H 2 O Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

2) What is the pH after mL of the base has been added? Titration of a Weak Acid with a Strong Base HC 2 H 3 O 2 ↔ C 2 H 3 O H 2 O Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH. R HC 2 H 3 O 2 OH -  H2OH2OC2H3O2-C2H3O2- I (0.2M)(25x10 -3 L) =0.005 (0.2M)(10x10 -3 L) = C Final HC 2 H 3 O 2 + OH -  C 2 H 3 O H 2 O R [HC 2 H 3 O 2 ] ↔ [H+][H+][C2H3O2-][C2H3O2-] I 0.003mol/35x10 -3 L = M mol/35x10 -3 L =0.057 M C -x+x E 0.2-xxx Convert to M (divide by 35 x L) Use moles in this chart!

3) What is the pH when 25 mL of the base is added? Titration of a Weak Acid with a Strong Base At the equivalence point, for a strong acid with a strong base, the pH = ______. This is not the case for a weak acid problem. Why? HC 2 H 3 O 2 + Na + + OH -  Na + + C 2 H 3 O H 2 O Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

4)What is the pH after 26 mL of NaOH has been added? Titration of a Weak Acid with a Strong Base After the equivalence point has been reached, the additional OH -- has nothing left to react with so the pH is determined by ______________________________. 25mL reacts, 1mL of NaOH left Ex. 25.0mL of M HC 2 H 3 O 2 is titrated with M NaOH.

Conclusions for Titrations of Weak Acids 1.The pH of a weak acid is ___________ initially than a strong acid of the same concentration because 2.The pH rises rapidly in the early part of a titration, but more slowly near the _____________ ________ because 3.The pH at the equivalence point is not _________ because

Titration of a Weak Acid with a Strong Base HC 2 H 3 O 2 NaOH The titration curve for a weak acid with a strong base is similar to the curve for a strong acid with a strong base. Construct a titration curve for this problem and compare it to the curve for a strong/strong titration.