# Volumetric Analysis. Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115

Save this PDF as:

Size: px
Start display at page:

Download "Volumetric Analysis. Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115"

## Transcription

1 Volumetric Analysis Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115

2 Experimental Aims To prepare and standardize (determine concentration) a NaOH solution Using your standardized NaOH calculate the molar concentration of a strong acid (HCl) HOW? Through titration

3 Techniques Titration Need reproducible results 3 trials are performed (3 titrations) Accuracy is important

4

5 Lab Outline The concentration of a sodium hydroxide will be determined by titration with potassium hydrogen phthalate, (KHC 8 H 4 O 4 = KHP) Using the determined concentration of your sodium hydroxide solution, this will be titrated with a HCl solution to calculate its concentration.

6 Points to Note Your solution of sodium hydroxide will be pre-made. Page 111, Preparing a stock solution does not need to be performed. Your sample of KHP are already dried.

7 Introduction Titration is a common method of determining the amount or concentration of an unknown substance. The method is easy to use if the quantitative relationship between two reacting solutions is known. The method is particularly well-suited to acid-base and oxidation-reduction reactions. Titrations are routinely used in industry to analyze products to be sold. Many manufacturers are under strict standards of quality control because their products are sold for public consumption.

8 Background In a titration a solution of one reactant (the titrant) is added to a measure amount of a second reactant. One of these reactants is called a standard (known concentration or molar mass) and the other is unknown (reactant). A color change (or some distinctive change) occurs when enough titrant has been added to consume all the reactant in the analyte. In this acid-base titration we make use of the general reaction: OH - + HA H 2 O + A -

9 What is an acid-base indicator? An acid-base indicator is a weak acid or a weak base. The undissociated form of the indicator is a different color than the associated form of the indicator. An Indicator does not change color from pure acid to pure alkaline at specific hydrogen ion concentration, but rather, color change occurs over a range of hydrogen ion concentrations. This range is termed the color change interval. It is expressed as a ph range.

10 How is an indicator used? Weak acids are titrated in the presence of indicators which change under slightly alkaline conditions. Weak bases should be titrated in the presence of indicators which change under slightly acidic conditions

11 Background Information Arrhenius Acids acids produce H + ions in aqueous solutions bases produce OH - ions in aqueous solutions water required, so only allows for aqueous solutions only protic acids are allowed; required to produce hydrogen ions only hydroxide bases are allowed

12 Brønsted Lowry Acids acids are proton donors bases are proton acceptors aqueous solutions are permissible bases besides hydroxides are permissible only protic acids are allowed Lewis Definition acids are electron pair acceptors bases are electron pair donors least restrictive of acid-base definitions

13 The equivalence point of a titration When you carry out a simple acid-base titration, you use an indicator to tell you when you have the acid and alkali mixed in exactly the right proportions to "neutralise" each other. When the indicator changes color, this is often described as the end point of the titration. In an ideal world, the color change would happen when you mix the two solutions together in exactly equation proportions. That particular mixture is known as the equivalence point.

14 Example If you were titrating sodium hydroxide solution with hydrochloric acid, both with a concentration of 1 mol dm -3, 25 cm 3 of sodium hydroxide solution would need exactly the same volume of the acid - because they react 1 : 1 according to the equation. In this particular instance, this would also be the neutral point of the titration, because sodium chloride solution has a ph of 7.

15 This is not necessarily true of all the salts you might get formed. If you titrate ammonia solution with hydrochloric acid, you would get ammonium chloride formed. The ammonium ion is slightly acidic, and so pure ammonium chloride has a slightly acidic ph. That means that at the equivalence point (where you had mixed the solutions in the correct proportions according to the equation), the solution wouldn't actually be neutral. To use the term "neutral point" in this context would be misleading.

16 Similarly: If you titrate sodium hydroxide solution with ethanoic acid, at the equivalence point the pure sodium ethanoate formed has a slightly alkaline ph because the ethanoate ion is slightly basic. NaOH + CH 3 COOH CH 3 COONa + H 2 O

17 The term "neutral point" is best avoided. The term "equivalence point" means that the solutions have been mixed in exactly the right proportions according to the equation. The term "end point" is where the indicator changes color, and this isn't necessarily exactly the same as the equivalence point.

18 Titration curves for strong acid v strong base HCl and NaOH are typical strong acid and strong base. Running acid into the alkali You can see that the ph only falls a very small amount until quite near the equivalence point. Then there is a really steep plunge. If you calculate the values, the ph falls all the way from 11.3 when you have added 24.9 cm 3 to 2.7 when you have added 25.1 cm 3.

19 Alkali to Acid Titration This is very similar to the previous curve except, of course, that the ph starts off low and increases as you add more sodium hydroxide solution.

20 Strong Acids and Bases Don't confuse the words strong and weak with the terms concentrated and dilute. The strength of an acid is related to the proportion of it which has reacted with water to produce ions. The concentration tells you about how much of the original acid is dissolved in the solution. It is perfectly possible to have a concentrated solution of a weak acid, or a dilute solution of a strong acid.

21 Strong Acids and ph ph is a measure of the concentration of hydrogen ions in a solution. Strong acids like hydrochloric acid at the sort of concentrations you normally use in the lab have a ph around 0 to 1. The lower the ph, the higher the concentration of hydrogen ions in the solution

22 Defining ph

23 Example If you had to work out the ph of 0.1 mol dm -3 hydrochloric acid. All you have to do is work out the concentration of the hydrogen ions in the solution, and then use your calculator to convert it to a ph. With strong acids this is easy. Hydrochloric acid is a strong acid - virtually 100% ionised. Each mole of HCl reacts with the water to give 1 mole of hydrogen ions and 1 mole of chloride ions

24 That means that if the concentration of the acid is 0.1 mol dm -3, then the concentration of hydrogen ions is also 0.1 mol dm -3. Use your calculator to convert this into ph. My calculator wants me to enter 0.1, and then press the "log" button. Yours might want you to do it in a different order. You need to find out! log 10 [0.1] = -1 But ph = - log 10 [0.1] - (-1) = 1 The ph of this acid is 1.

25 Standardization of NaOH A standard solution is one in which the concentration is known accurately. A standard solution of NaOH will be prepared. One way to prepare a standard solution is to dissolve an accurately massed amount of the substance and dilute it to a measured volume In this way, the concentration can be calculated exactly. Molarity = No of moles / Vol in liters

26 NaOH Standardization It is usually impossible to obtain NaOH of sufficient purity to use it as a primary standard. Why? Sodium Hydroxide is hygroscopic (picks up water from the air) An indirect method is more practical for obtaining a standard solution of NaOH. A solution of a approximate molarity will be prepared and standardized against a primary standard of known purity.

27 What is a primary standard? A sample that is of high purity Remain unchanged in air during massing and remain stable during storage Have a high molar mass to reduce massing errors React with the solution to be standardized in a direct, well-defined reaction

28 Potassium acid phthalate will serve as our primary standard. This is a large molecule (KHC 8 H 4 O 4 ) with a molar mass of g/mol. Instead of writing the whole formula, it can be abbreviated as KHP, where "P" stands for the phthalate ion, C 8 H 4 O 4 2-, not for phosphorus. KHP is an acidic substance, with the ionizing hydrogen being set forward in the formula for emphasis. Therefore, KHP is monoprotic and will react with NaOH in a simple 1 to 1 relationship.

29 NaOH(aq) + KHC 8 H 4 O 4 (aq) KNaC 8 H 4 O 4 (aq) + H 2 O(l) The ionic equation is: Na + (aq) + OH - (aq) + K + (aq) + HC 8 H 4 O 4- (aq) Na + (aq) + K + (aq) + H 2 O(l) + C 8 H 4 O 4 2- (aq) If the spectator ions (Na +, K + ) are removed: OH - (aq) + HC 8 H 4 O 4- (aq) H 2 O(l) + C 8 H 4 O 4 2- (aq) This allows the following equation which applies at the endpoint* of the titration: Moles acid used = Moles base used

30 Equivalence and End Points OH - + HA H 2 O + A - The equivalence point is when equal moles of OH- have been added to HA because they react in a 1:1 ratio This can be difficult to determine, and instead use the end point Near the equivalence point of an acid base titration, the ph of the solution changes rapidly with relative amounts of HA and OH -, and this changes the color of the indicator As the end point is approached a color change will be observed when 1 drop of titrant hits the analyte Try to reach the point where addition of 1 drop of titrant causes a permanent color change (> 10 secs) after swirling

31 Procedure The base (NaOH) will be standardized with KHP. This standard base will be used to standardize the acid so that the exact concentrations of both solutions will be known and can then easily titrate and analyze unknowns.

32 Procedure You will be given a solution of 0.1xx M NaOH. This will be your titrant. Rinse a buret with water and then with a small amount of the NaOH solution. Fill the buret with NaOH solution. Fill the buret tip by momentarily opening the stopcock. Read the initial volume. Accurately weigh approx. 0.8xx g of KHP into a 250 ml Erlenmeyer flask. Add about 100 ml of water and swirl the flask until the sample is dissolved. Add 3 drops of phenolphthalein indicator (colorless in acidic solution; pink in basic solution).

33 Titrate the KHP solution with the base solution to be standardized. Titration should proceed until the faintest pink persists for 30 sec. after swirling. The color will fade upon exposure to the air (WHY?) After completing a trial, breathe into the flask and swirl. What has happened? Make duplicate determinations and calculate the average molarity of the NaOH. For excellent work, the molarities need to be within 1% of one another.

34 Analysis of an Unknown Acid Obtain an unknown acid and perform 3 titrations You substitute your acid for KHP Check for precision of these titrations

35 Data (for each trial): Mass of KHP in sample flask Initial buret reading Final buret reading Volume of NaOH required to neutralize the KHP

36 Experimental Techniques Near the endpoint of the titration, you may want to add a fraction of a drop instead of a whole drop. To do this, let a little droplet grow out on the tip of the buret. Then wash it into the flask with a squirt of distilled water from your wash bottle

37 You will know when you are getting close to the endpoint because addition of a small amount of NaOH (as little as a drop) will produce a pink color that will take a long time to fade as the flask is swirled. You have reached the endpoint of the titration when addition of one drop or less of solution causes the solution in the flask to turn pink and stay pink for 10 seconds or longer.

38 Once the endpoint has been reached, read the final volume off of the buret. Here a volume of 42.5mls is read The volume of NaOH solution added to the flask is simply the final volume reading minus the initial volume reading.

39 Example Calculation Let's assume that we started with g of KHP and it took ml of NaOH to reach the endpoint, what value of [NaOH] do you get from this equation? I get a value of M. (Note: These numbers are totally bogus. When you do the experiment use your actual numbers for this calculation).

40 Example 2 In a titration 23.25mls of NaOH, 0.125M was needed to react with mls HCl. What is the molarity of the acid?

41 Example 3 If 250mls of a 0.1M NaOH solution was required. How many grams would need to be weighed?

42 More Examples Calculate the molarity of a solution prepared by dissolving 4g NaOH in 100mls of solution? If 25mls of a 0.56M H2SO4 solution is diluted to a volume of 125mls. What is the molarity of the resulting solution?

43 Clean Up Dispose of excess NaOH solution in the surplus NaOH bottle in the hood Dispose of excess acidic solutions in correctly labeled bottle Rinse the buret thoroughly with deionized water and place upside down in buret clamp Wipe down benches Put away equipment

### Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration

Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration GOAL AND OVERVIEW Antacids are bases that react stoichiometrically with acid. The number of moles of acid that

### The introduction of your report should be written on the on the topic of the role of indicators on acid base titrations.

Experiment # 13A TITRATIONS INTRODUCTION: This experiment will be written as a formal report and has several parts: Experiment 13 A: Basic methods (accuracy and precision) (a) To standardize a base (~

### Acids and Bases. Chapter 16

Acids and Bases Chapter 16 The Arrhenius Model An acid is any substance that produces hydrogen ions, H +, in an aqueous solution. Example: when hydrogen chloride gas is dissolved in water, the following

### 1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11

SCH3U- R.H.KING ACADEMY SOLUTION & ACID/BASE WORKSHEET Name: The importance of water - MAKING CONNECTION READING 1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436

### I N V E S T I C E D O R O Z V O J E V Z D Ě L Á V Á N Í CHEMICAL REACTIONS

Chemical reaction = process during which original substances change to new substances, reactants turn to... The bonds of reactants... and new bonds are... The classification of reactions: 1. Classification

### Acid-Base (Proton-Transfer) Reactions

Acid-Base (Proton-Transfer) Reactions Chapter 17 An example of equilibrium: Acid base chemistry What are acids and bases? Every day descriptions Chemical description of acidic and basic solutions by Arrhenius

### CHM 130LL: ph, Buffers, and Indicators

CHM 130LL: ph, Buffers, and Indicators Many substances can be classified as acidic or basic. Acidic substances contain hydrogen ions, H +, while basic substances contain hydroxide ions, OH. The relative

### Q1: What is the ph Scale? Q6: As acids become more acidic, their ph values

Q1: What is the ph Scale? Q6: As acids become more acidic, their ph values increase or decrease? Q2: The range of values of the ph scale is: Q7: As bases become more alkaline, their ph values increase

### 4. Acid Base Chemistry

4. Acid Base Chemistry 4.1. Terminology: 4.1.1. Bronsted / Lowry Acid: "An acid is a substance which can donate a hydrogen ion (H+) or a proton, while a base is a substance that accepts a proton. B + HA

### Chapter 13 & 14 Practice Exam

Name: Class: Date: Chapter 13 & 14 Practice Exam Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Acids generally release H 2 gas when they react with a.

### Name: Class: Date: 2 4 (aq)

Name: Class: Date: Unit 4 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The balanced molecular equation for complete neutralization of

### 1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) 3 (s) + H 2 (g)

1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) A) 1 B) 2 C) 4 D) 5 E) Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) Al (s) + H 2 O (l)? Al(OH)

### 1. To perform a potentiometric titration of a sample of Liquid Drano with hydrochloric acid.

INTRODUCTION ANALYSIS OF DRAIN CLEANER (Revised: 1-25-93) Many common household cleaners contain acids or bases. Acidic cleaners, such as toilet bowl cleaners, often contain hydrochloric acid or sodium

### Experiment 18: ph Measurements of Common Substances. Experiment 17: Reactions of Acids with Common Substances

Experiment 18: ph Measurements of Common Substances and Experiment 17: Reactions of Acids with Common Substances What is this lab about? You mean what ARE THESE labs about? Ok, so what are THESE labs about?

### Sketch the model representation of the first step in the dissociation of water. H 2. O (l) H + (aq) + OH- (aq) + H 2. OH - (aq) + H 3 O+ (aq)

Lesson Objectives Students will: Create a physical representation of the autoionization of water using the water kit. Describe and produce a physical representation of the dissociation of a strong acid

### Guide To Preparation of Stock Standard Solutions

chemias ft Guide To Preparation of Stock Standard Solutions First Edition May 2011 Na+ 1000 ppm Guide To Preparation Of Stock Standard Solutions By: CHEMIASOFT May 2011 Page 2 of 61 Page 3 of 61 Table

### Experiment 9: Acids and Bases Adapted from: Chemistry, Experimental Foundations, 4th Ed. Laboratory Manual, by Merrill, Parry & Bassow.

Chem 121 Lab Clark College Experiment 9: Acids and Bases Adapted from: Chemistry, Experimental Foundations, 4th Ed. Laboratory Manual, by Merrill, Parry & Bassow. Content Goals: Increase understanding

### Experiment 3: Extraction: Separation of an Acidic, a Basic and a Neutral Substance

1 Experiment 3: Extraction: Separation of an Acidic, a Basic and a Neutral Substance Read pp 142-155, 161-162, Chapter 10 and pp 163-173, Chapter 11, in LTOC. View the videos: 4.2 Extraction (Macroscale);

### Continuous process of sodium bicarbonate production by Solvay method

Continuous process of sodium bicarbonate production by Solvay method Manual to experiment nr 10 Instructor: Dr Tomasz S. Pawłowski 1 Goal of the experiment The goal of the experiment is introduction of

### Solutions and Dilutions

Learning Objectives Students should be able to: Content Design a procedure for making a particular solution and assess the advantages of different approaches. Choose the appropriate glassware to ensure

### ACIDS AND BASES SAFETY PRECAUTIONS

ACIDS AND BASES Mild acids and bases are used in cooking (their reaction makes biscuits and bread rise). Acids such as those in our stomachs eat away at food or digest it. Strong acids and bases are used

### Hot water extractable acidity or alkalinity of paper (Reaffirmation of T 428 om-08) (No changes from Draft 1)

NOTICE: This is a DRAFT of a TAPPI Standard in ballot. Although available for public viewing, it is still under TAPPI s copyright and may not be reproduced or distributed without permission of TAPPI. This

### Chapter 6. Solution, Acids and Bases

Chapter 6 Solution, Acids and Bases Mixtures Two or more substances Heterogeneous- different from place to place Types of heterogeneous mixtures Suspensions- Large particles that eventually settle out

### Chapter 8, Acid-base equilibria

Chapter 8, Acid-base equilibria Road map of acid-base equilibria On first encounter, the study of acid-base equilibria is a little like a strange land with seemingly confusing trails that make passage

### Chapter 14 Solutions

Chapter 14 Solutions 1 14.1 General properties of solutions solution a system in which one or more substances are homogeneously mixed or dissolved in another substance two components in a solution: solute

### Chapter 1 The Atomic Nature of Matter

Chapter 1 The Atomic Nature of Matter 6. Substances that cannot be decomposed into two or more simpler substances by chemical means are called a. pure substances. b. compounds. c. molecules. d. elements.

### 1. What do you think is the definition of an acid? Of a base?

Concepts of ph Why? The level of acidity or basicity affects many important biological and environmental processes: enzymes function effectively only in narrowly defined ranges of ph; blood ph in part

### Chemistry 2014 Scoring Guidelines

AP Chemistry 2014 Scoring Guidelines 2014 The College Board. College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College

### 6.8 Measuring the Acidity of Solutions Page 160

6.8 Measuring the Acidity of Solutions Page 160 PRESCRIBED LEARNING OUTCOMES measure substances and solutions according to ph, solubility, and concentration KNOWLEDGE ph is the measure of the tendency

### Ch 15: Acids and Bases

Ch 15: Acids and Bases A c i d s a n d B a s e s C h 1 5 P a g e 1 Homework: Read Chapter 15 Work out sample/practice exercises in the sections, Bonus problems: 39, 41, 49, 63, 67, 83, 91, 95, 99, 107,

### Lab 5: Quantitative Analysis- Phosphates in Water By: A Generous Student. LBS 171L Section 9 TA: Dana October 27, 2005

How uch Phosphate is the Body Being Exposed to During a Lifetime by Showering? Lab 5: Quantitative Analysis- Phosphates in Water By: A Generous Student LBS 171L Section 9 TA: Dana October 7, 005 [Note:

### Acid 7 Base. 1. Describe two things hydrochloric acid does in your body system. 2. What does sodium hydrogencarbonate do in your body system?

Acids and Bases acid: a compound that, when dissolved in water, forms a solution with a ph less than 7 base: a compound that, when dissolved in water, forms a solution with a ph greater than 7 ph: the

### Definition The property of exhibiting the qualities of a base

Acids and Bases Word Acidity Alkalinity Amphiprotic Amphoteric Arrhenius Acid Arrhenius Base Basicity Bronsted/Lowry Acid Bronsted/Lowry Base Buret Caustic Conjugate pair Corrosive Electrolyte Hydrolysis

### Standard Operating Procedure for Total Kjeldahl Nitrogen (Lachat Method)

Standard Operating Procedure for Total Kjeldahl Nitrogen (Lachat Method) Grace Analytical Lab 536 South Clark Street 10th Floor Chicago, IL 60605 April 15, 1994 Revision 2 Standard Operating Procedure

### UNITS OF CONCENTRATION

UNITS OF CONCENTRATION There are a number of different ways of expressing solute concentration that are commonly used. Some of these are listed below. Molarity, M = moles solute/liter of solution Normality,

### Chemistry 201. Practical aspects of buffers. NC State University. Lecture 15

Chemistry 201 Lecture 15 Practical aspects of buffers NC State University The everyday ph scale To review what ph means in practice, we consider the ph of everyday substances that we know from experience.

### Chemistry Final Study Guide

Name: Class: Date: Chemistry Final Study Guide Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The electrons involved in the formation of a covalent bond

### AP Chemistry 2006 Free-Response Questions

AP Chemistry 006 Free-Response Questions The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission is to connect students to college

### ph Measurements of Common Substances

Chem 100 Section Experiment 10 Name Partner s Name Introduction ph Measurements of Common Substances The concentration of an acid or base is frequently expressed as ph. Historically, ph stands for the

### Acid-base Equilibria and Calculations

Acid-base Equilibria and Calculations A Chem1 Reference Text Stephen K. Lower Simon Fraser University Contents 1 Proton donor-acceptor equilibria 4 1.1 The ion product of water... 4 1.2 Acid and base strengths...

### Coimisiún na Scrúduithe Stáit State Examinations Commission

Coimisiún na Scrúduithe Stáit State Examinations Commission LEAVING CERTIFICATE EXAMINATION, 2007 CHEMISTRY - ORDINARY LEVEL TUESDAY, 19 JUNE AFTERNOON 2.00 TO 5.00 400 MARKS Answer eight questions in

### Mass of thoroughly dried filter paper. Mass of filter paper + precipitate after third drying. Mass of filter paper + precipitate after second drying

Mass of KI tablet Mass of thoroughly dried filter paper Mass of filter paper + precipitate after first drying Mass of filter paper + precipitate after second drying Mass of filter paper + precipitate after

### Chapter 2 Polar Covalent Bonds: Acids and Bases

John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds: Acids and Bases Modified by Dr. Daniela R. Radu Why This Chapter? Description of basic ways chemists account for chemical

### Related concepts Kohlrausch s law, equivalent conductivity, temperature dependence of conductivity, Ostwald s dilution law.

Conductivity of strong and weak electrolytes TEC Related concepts Kohlrausch s law, equivalent conductivity, temperature dependence of conductivity, Ostwald s dilution law. Principle It is possible to

### Oakland Schools Chemistry Resource Unit. Acid Base Concepts. Karen Doree South Lyon East High School South Lyon Community Schools

Oakland Schools Chemistry Resource Unit Acid Base Concepts Karen Doree South Lyon East High School South Lyon Community Schools 1 Content Statements: C5.7 Acid-Base Concepts Acids and bases are important

### Estimation of Alcohol Content in Wine by Dichromate Oxidation followed by Redox Titration

Sirromet Wines Pty Ltd 850-938 Mount Cotton Rd Mount Cotton Queensland Australia 4165 www.sirromet.com Courtesy of Jessica Ferguson Assistant Winemaker & Chemist Downloaded from seniorchem.com/eei.html

### English already has many collective nouns for fixed, given numbers of objects. Some of the more common collective nouns are shown in Table 7.1.

96 Chapter 7: Calculations with Chemical Formulas and Chemical Reactions Chemical reactions are written showing a few individual atoms or molecules reacting to form a few atoms or molecules of products.

### AP Chemistry 2015 Free-Response Questions

AP Chemistry 2015 Free-Response Questions College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. AP Central is the official online

### Calibration of Volumetric Glassware

CHEM 311L Quantitative Analysis Laboratory Revision 2.3 Calibration of Volumetric Glassware In this laboratory exercise, we will calibrate the three types of glassware typically used by an analytical chemist;

### Acid-base Chemistry of Aquatic Systems

i Acid-base Chemistry of Aquatic Systems An introduction to the chemistry of acid-base equilibria with emphasis on the carbon dioxide system in natural waters eith A. Hunter Professor in Chemistry Department

### Determining the Quantity of Iron in a Vitamin Tablet. Evaluation copy

Determining the Quantity of Iron in a Vitamin Tablet Computer 34 As biochemical research becomes more sophisticated, we are learning more about the role of metallic elements in the human body. For example,

### Letter to the Student... 5 Test-Taking Checklist... 6 Next Generation Sunshine State Standards Correlation Chart... 7

Table of Contents Letter to the Student..................................... 5 Test-Taking Checklist.................................... 6 Next Generation Sunshine State Standards Correlation Chart...

### Chapter 3 Stoichiometry

Chapter 3 Stoichiometry 3-1 Chapter 3 Stoichiometry In This Chapter As you have learned in previous chapters, much of chemistry involves using macroscopic measurements to deduce what happens between atoms

Candidate Style Answer Chemistry A Unit F321 Atoms, Bonds and Groups High banded response This Support Material booklet is designed to accompany the OCR GCE Chemistry A Specimen Paper F321 for teaching

### Phosphates (ortho- and total)

INTRODUCTION Phosphates (ortho- and total) Phosphorus is an essential nutrient for all aquatic plants and algae. Only a very small amount is needed, however, so an excess of phosphorus can easily occur.

### Acid-Base Extraction.

Acid-Base Extraction. Extraction involves dissolving a compound or compounds either (1) from a solid into a solvent or (2) from a solution into another solvent. A familiar example of the first case is

### 7. 1.00 atm = 760 torr = 760 mm Hg = 101.325 kpa = 14.70 psi. = 0.446 atm. = 0.993 atm. = 107 kpa 760 torr 1 atm 760 mm Hg = 790.

CHATER 3. The atmosphere is a homogeneous mixture (a solution) of gases.. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. have volumes that depend on their conditions,

### The energy level diagram for this reaction is shown below.

Q. Methanol can be made when methane reacts with oxygen. (a) The energy level diagram for this reaction is shown below. (i) What is the energy change represented by A? () (ii) Use the energy level diagram

### Acids and Bases 7. Have You Ever Wondered?

Acids and Bases 7 Have You Ever Wondered? 1. Are all acids corrosive? 2. What is an amino acid? 3. Is vitamin C really an acid? Are all vitamins acids? 4. What is the difference between salt and sodium?

### AP*Chemistry The Chemistry of Acids and Bases

AP*Chemistry The Chemistry of Acids and Bases "ACID"--Latin word acidus, meaning sour. (lemon) "ALKALI"--Arabic word for the ashes that come from burning certain plants; water solutions feel slippery and

### Acids and Bases. Problem Set: Chapter 17 questions 5-7, 9, 11, 13, 18, 43, 67a-d, 71 Chapter 18 questions 5-9, 26, 27a-e, 32

Acids and Bases Problem Set: Chapter 17 questions 5-7, 9, 11, 13, 18, 43, 67a-d, 71 Chapter 18 questions 5-9, 26, 27a-e, 32 Arrhenius Theory of Acids An acid base reaction involves the reaction of hydrogen

### Prentice Hall. Chemistry (Wilbraham) 2008, National Student Edition - South Carolina Teacher s Edition. High School. High School

Prentice Hall Chemistry (Wilbraham) 2008, National Student Edition - South Carolina Teacher s Edition High School C O R R E L A T E D T O High School C-1.1 Apply established rules for significant digits,

### Four common concentration units 1. Molarity 2. Weight Percent (Wt %), ppm, ppb 3. Molality 4. Mole Fraction. Molarity, M =

Four common concentration units 1. Molarity 2. Weight Percent (Wt %), ppm, ppb 3. Molality 4. Mole Fraction Molarity, M tells you how many s of solute are present in every liter of solution (solute-to-solution)

### Calibration of Volumetric Glassware

Chemistry 119: Experiment 2 Calibration of Volumetric Glassware For making accurate measurements in analytical procedures, next in importance to the balance is volumetric equipment. In this section volumetric

### Solubility of Salts - Ksp. Ksp Solubility

Solubility of Salts - Ksp We now focus on another aqueous equilibrium system, slightly soluble salts. These salts have a Solubility Product Constant, K sp. (We saw this in 1B with the sodium tetraborate

### Assessment of Accuracy and Precision

2 chapter Assessment of Accuracy and Precision S.S. Nielsen, Food Analysis Laboratory Manual, Food Science Texts Series, DOI 10.1007/978-1-4419-1463-7_2, Springer Science+Business Media, LLC 2010 9 Chapter

### Laboratory Math II: Solutions and Dilutions

Slide 1 Laboratory Math II: Solutions and Dilutions Philip Ryan, PhD Post-Doctoral Fellow National Cancer Institute, NIH Welcome to the National Institutes of Health, Office of Intramural Training & Education

### (1) e.g. H hydrogen that has lost 1 electron c. anion - negatively charged atoms that gain electrons 16-2. (1) e.g. HCO 3 bicarbonate anion

GS106 Chemical Bonds and Chemistry of Water c:wou:gs106:sp2002:chem.wpd I. Introduction A. Hierarchy of chemical substances 1. atoms of elements - smallest particles of matter with unique physical and

### Stage 1 Desired Results

Lesson Title: Phosphate Testing Contract Discipline Focus: Chemistry Grade level: 11-12 Length of lesson: 1.5 class periods Content Standard(s): Stage 1 Desired Results Understanding (s)/goals Students

### Chemists use the ph value to measure how acidic or basic a solution is. The ph scale runs from 0 to 14:

The ph Value Chemists use the ph value to measure how acidic or basic a solution is. The ph scale runs from 0 to 14: If the ph value is lower than 7 (0 to 6.99) the solution contains more H + ions than

### Instructional Notes/Strategies. GLEs. Evidence / Assessments of learning Knowledge/Synthesis. Resources # SI-1 (E)

Lafayette Parish School System Curriculum Map Honors Chemistry (Pearson) Unit 1: Introduction to Chemistry Time Frame 1 week August 15 August 21, 2011 Unit Description - This unit focuses on Why It Is

### Balancing chemical reaction equations (stoichiometry)

Balancing chemical reaction equations (stoichiometry) This worksheet and all related files are licensed under the Creative Commons Attribution License, version 1.0. To view a copy of this license, visit

### Aquagent. Pyridine-free volumetric Karl Fischer reagents

Aquagent. Pyridine-free volumetric Karl Fischer reagents One-component reagents Two-component reagents Reagents for aldehyde and ketone analysis Working Media Dry solvents Standards Pyridine-free Fast

### Acid-Base Indicator Useful Indicators

Chemistry 101 - H Acids and Bases This presentation was created by Professor Carl H. Snyder Chemistry Department University of Miami Coral Gables, FL 33124 CSnyder@miami.edu Chapter 10 - Acids and Bases

### Calibration of Glassware

Calibration of Glassware Introduction Glassware is commonly calibrated using a liquid of known, specific density, and an analytical balance. The procedure is to determine the mass of liquid the glassware

### Household Acids and Bases

Household Acids and Bases GRADE LEVEL INDICATORS Experiment Demonstrate that the ph scale (0-14) is used to measure acidity and classify substances or solutions as acidic, basic, or neutral. 21 Develop

### = 1.038 atm. 760 mm Hg. = 0.989 atm. d. 767 torr = 767 mm Hg. = 1.01 atm

Chapter 13 Gases 1. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. Gases have volumes that depend on their conditions, and can be compressed or expanded by

INTDUCTIN T LEWIS ACID-BASE CEMISTY DEINITINS Lewis acids and bases are defined in terms of electron pair transfers. A Lewis base is an electron pair donor, and a Lewis acid is an electron pair acceptor.

### 5s Solubility & Conductivity

5s Solubility & Conductivity OBJECTIVES To explore the relationship between the structures of common household substances and the kinds of solvents in which they dissolve. To demonstrate the ionic nature

### Experiment 13: Determination of Molecular Weight by Freezing Point Depression

1 Experiment 13: Determination of Molecular Weight by Freezing Point Depression Objective: In this experiment, you will determine the molecular weight of a compound by measuring the freezing point of a

### Luminol Test PROCESS SKILLS SCIENCE TOPICS VOCABULARY

EXPERIMENT: LUMINOL TEST Luminol Test Visitors mix a solution of luminol with fake blood (hydrogen peroxide) to produce a reaction that gives off blue light. OBJECTIVES: Visitors learn that some chemical

### PROFESSIONAL DEVELOPMENT

PROFESSIONAL DEVELOPMENT AP Chemistry Acids and Bases Special Focus The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission

### a. pure substance b. composed of combinations of atoms c. held together by chemical bonds d. substance that cannot be broken down into simpler units

Chemical Bonds 1. Which of the following is NOT a true compound? a. pure substance b. composed of combinations of atoms c. held together by chemical bonds d. substance that cannot be broken down into simpler

### Lab 2 Biochemistry. Learning Objectives. Introduction. Lipid Structure and Role in Food. The lab has the following learning objectives.

1 Lab 2 Biochemistry Learning Objectives The lab has the following learning objectives. Investigate the role of double bonding in fatty acids, through models. Developing a calibration curve for a Benedict

### NITRIC OXIDE and NITROGEN DIOXIDE 6014

NITRIC OXIDE and NITROGEN DIOXIDE 6014 NO MW: 30.01 CAS: 10102-43-9 RTECS: QX0525000 46.01 10102-44-0 QW9800000 METHOD: 6014, Issue 1 EVALUATION: FULL Issue 1: 15 August 1994 OSHA : 25 ppm NO; C 1 ppm

### Nomenclature and Household Items

Nomenclature and Household Items NAME: DATE: PERIOD: Background: Many household items contain chemicals that are commonly used in everyday life. Some chemicals are edible while other compounds would be

### Forensic Science Standards and Benchmarks

Forensic Science Standards and Standard 1: Understands and applies principles of scientific inquiry Power : Identifies questions and concepts that guide science investigations Uses technology and mathematics

### Recrystallization II 23

Recrystallization II 23 Chem 355 Jasperse RECRYSTALLIZATIN-Week 2 1. Mixed Recrystallization of Acetanilide 2. Mixed Recrystallization of Dibenzylacetone 3. Recrystallization of an Unknown Background Review:

### Phosphorus Analyzer Procedure Last updated: 8.7.15. A. Introduction

Phosphorus Analyzer Procedure Last updated: 8.7.15 A. Introduction The phosphorus analyzer can be used to measure soluble reactive phosphorus (SRP) aka orthophosphate (PO 3-4 ) only. Additionally, this

### Chapter 6: Mixtures. Overall Objectives 46. 6.1 Introduction 46. Time Required: 6.2 Types of mixtures 46

Chapter 6: Mixtures Overall Objectives 46 6.1 Introduction 46 6.2 Types of mixtures 46 6.3 Like dissolved like 46 6.4 Soap 47 6.5 Summary 47 Experiment 6: Mix it Up! 48 Review 52 Notes 52 Time Required:

### Introduction, Noncovalent Bonds, and Properties of Water

Lecture 1 Introduction, Noncovalent Bonds, and Properties of Water Reading: Berg, Tymoczko & Stryer: Chapter 1 problems in textbook: chapter 1, pp. 23-24, #1,2,3,6,7,8,9, 10,11; practice problems at end

### How do scientists prepare solutions with specific concentrations of solutes?

EXERCISE 2 Name How do scientists prepare solutions with specific concentrations of solutes? Objectives After completing this exercise, you should be able to: define and correctly use the following terms:

### Standard Operating Procedures

Standard Operating Procedures 1 Standard Operating Procedures OVERVIEW In the following laboratory exercises you will be introduced to some of the glassware and techniques used by chemists to isolate components

### Customer application report

16 Cape Town drinking water monitoring solution from Metrohm On 28 July 2010, the General Assembly of the United Nations declared clean water and sanitation as a fundamental human right! This underlines

### North East Regional Heat Schools Analyst Competition 2013. Coral in Distress

RSC NERAD Schools Analyst Competition 2013 Laboratory Handbook Page 1 North East Regional Heat Schools Analyst Competition 2013 Coral in Distress LABORATORY HANDBOOK Royal Society of Chemistry Analytical

### METHODS FOR THE EVALUATION OF ANALYTICAL FILTER PAPERS

U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS RESEARCH PAPER RP1653 Part of Journal of Research of the National Bureau of Standards, Volume 34, May 1945 METHODS FOR THE EVALUATION OF ANALYTICAL