Qualitative Analysis of Unknown Compounds

Size: px
Start display at page:

Download "Qualitative Analysis of Unknown Compounds"

Transcription

1 Qualitative Analysis of Unknown Compounds 1. Infrared Spectroscopy Identification of functional groups in the unknown All functional groups are fair game (but no anhydride or acid halides, no alkenes or alkynes) 2. Elemental Analysis Determination of the Empirical Formula of the Unknown Smallest whole number ratio of elements in the formula (mole ratio of elements) 3. Mass Spectral Analysis Determination of the Molecular Formula of the Unknown Actual number of atoms in the formula Molecular Weight of the Unknown Halide identification 4. Proton NMR Symmetry: the number of chemically different protons Chemical Shift: chemical environment of protons (e- rich or e- poor) Integration: ratio of protons Splitting Patterns: arrangement of neighboring protons (how many next door) 5. Carbon-13 NMR Symmetry: number of chemically different Carbons Chemical Shift: chemical environment of Carbons (e- rich or e- poor) Also: Splitting Patterns Number of attached protons (not required for unknowns, only for lab exam) Elemental Analysis the empirical formula Ex. Calculate the empirical formula for a compound whose elemental analysis is the following: %C = %H = %O = How to do? Convert percentages to grams Assume the 100% from the formula is 100 grams total, and thus all the percents can become grams. Then, convert grams to moles by dividing by the atomic weights: %C = 47.35/ = 3.94 %H = 10.60/1.008 = %O = 42.05/ = 2.62 To obtain the smallest whole number ratio (i.e. mole ratio of elements, the empirical formula), divide each by the smallest value: %C = 47.35/ = 3.94/2.62 = 1.5 %H = 10.60/1.008 = /2.62 = 4 %O = 42.05/ = 2.62/2.62 = 1 1

2 How do you deal with a half factor or a third factor? Multiply all values by 2 or 3 Empirical Formula = C 3 H 8 O 2 Mass Spectroscopy v Used to measure molecular mass v Typically used to determine the molecular weight of a compound v The Process: Ionization of a compound caused by loss of an electron, results in the formation of a species that is positively charged the cation radical called the Molecular Ion. No longer neutral, the molecular ion fragments after formation, into smaller pieces, some of which are radicals and some that are cations. The cations are detected in the instrument and sorted according to mass. The x-axis mass-to-charge ratio (m/z) = the mass of the fragments, because the charge is always +1. The y-axis of a mass spectrum is Relative Abundance = the relative number of times a cation fragment appears in the detector. The most abundant fragment is arbitrarily assigned the value of 100% (999/1000 on your tables) and the amounts of the other fragments is measured relative to this fragment, referred to as the Base Peak. The initial cation radical contains all the atoms of the original compound and is only missing one electron, of negligible weight. Thus the Molecular Ion has the same mass as the original compound. Using the molecular ion, and the empirical formula, one can determine the molecular formula for a compound. 2

3 Consider a compound whose empirical formula is C 2 H 5. This empirical formula weighs 29 a.m.u. The molecular ion appears at 58 a.m.u. What s the numerical relationship? Since the molecular ion weighs twice that of the weight of the empirical formula, you know you need to double the empirical formula to find the true molecular formula or (2 x C 2 H 5 ) or C 4 H 10. Determine the molecular formula for a compound whose molecular ion is 73 and contains carbon, hydrogen and nitrogen. Begin with the non-carbon/non-hydrogen atoms - Nitrogen, 14 amu = 59 How many Carbons fit into 59? 4 Carbons weigh = 11 Empirical Formula = C 4 H 11 N. Draw a structure that corresponds to this molecular formula, C 4 H 11 N. Determine how many unsaturations exist: UN = #C ½ (H + X) + ½ (N) +1 Possible structures? Identification of Halides: Review: Isotopes are variations of the same elements, with differing numbers of neutrons in the nucleus. 1. Chlorides: Cl 35, Cl 37 Isotopes occur in a 3:1 abundance ratio in nature. The molecular ion, by definition, must contain the Cl 35 isotope, and a second major peak appears two units higher for those molecules that contain the Cl 37 isotope. Required Peaks to identify: M + (total weight, including isotope Cl 35 ) = 78 (see below) M+2 (total weight, including isotope Cl 37 ) = 80 Below is the MS for 1-chloropropane: 3

4 2. Bromides: Br 79, Br 81 Isotopes occur in about a 1:1 abundance ratio in nature. The molecular ion, by definition, must contain the Br 79 isotope, and a second major peak appears two units higher for those molecules that contain the Br 81 isotope. Required Peaks to identify: M + (total weight, including isotope Br 79 ) = 108 (see below) M+2 (total weight, including isotope Br 81 ) = 110 Below is the MS for bromoethane: 4

5 How does one determine which peak is the molecular ion? Since it encompasses the molecular weight of the entire compound (minus only one electron), it will be one of the highest mass peaks, found on the far right of the spectrum but is NOT necessarily the furthest peak on the right, due to the existence of isotopes. Isotopes of atoms have different weights. While the average mass of hydrogen may be amu, the MS detector only sees the specific isotopes, hydrogen-1, deuterium (hydrogen-2) and/or tritium (hydrogen-3) involved in a fragment. You cannot use AVERAGES when dealing with your mass spectra. Stay away from the values shown on the periodic table. By definition, the molecular ion always contains the following isotopes only: Carbon-12, Hydrogen-1, Oxygen-16 and Nitrogen-14. The halides are always the lower of the two isotope pairs, Chlorine-35 and Bromine-79. Now: Tie Elemental Analysis and Mass Spectroscopy Together 1. Calculate the Empirical Formula. Consider Unknown Compound X has an empirical formula of C 6 H 15 N (101 a.m.u.): The Mass Spectrum for Compound X shows a series of peaks on far right of spectrum at 100, 101 and 102. Which peak is the molecular ion? The molecular ion MUST either MATCH or be a multiple of the weight of the empirical formula. If C 6 H 15 N weighs 101 amu, then the molecular ion must equal 101 or 202 or 303. When the weight of the molecular ion matches the weight of the empirical formula, you know that the empirical formula IS the molecular formula: C 6 H 15 N. 5

6 2. Consider Unknown Compound Y has an empirical formula of C 4 H 9 O (73 a.m.u.): As you can see, the Mass Spectrum for Compound Y shows multiple peaks above 73. AS such, C 4 H 9 O cannot be the molecular formula. Try doubling or tripling the weight of the empirical formula it to see where it matches the molecular ion (146, 219, etc.) On the spectrum, you ll see a molecular ion peak at 146. What is the molecular formula for Compound Y? The molecular ion must be 146 and the molecular formula is C 8 H 18 O 2. 6

7 Qual Lab: You will have TWO separate, different unknown compounds. For each you will: 1. Determine your empirical formulas 2. Determine your molecular ions and 3. Determine your molecular formulas for each unknown. 4. Analyze your IR s and proton NMR s to determine your functional groups and build the structure (carbon skeleton) of your molecule. 7

5. Carbon-13 NMR Symmetry: number of chemically different Carbons Chemical Shift: chemical environment of Carbons (e- rich or e- poor)

5. Carbon-13 NMR Symmetry: number of chemically different Carbons Chemical Shift: chemical environment of Carbons (e- rich or e- poor) Qualitative Analysis of Unknown Compounds 1. Infrared Spectroscopy Identification of functional groups in the unknown All functional groups are fair game (but no anhydride or acid halides, no alkenes or

More information

Identification of functional groups in the unknown Will take in lab today

Identification of functional groups in the unknown Will take in lab today Qualitative Analysis of Unknown Compounds 1. Infrared Spectroscopy Identification of functional groups in the unknown Will take in lab today 2. Elemental Analysis Determination of the Empirical Formula

More information

OAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry

OAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry OAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry Question No. 1 of 10 Question 1. Which statement concerning NMR spectroscopy is incorrect? Question #01 (A) Only nuclei

More information

CHEM 241 UNIT 5: PART A DETERMINATION OF ORGANIC STRUCTURES BY SPECTROSCOPIC METHODS [MASS SPECTROMETRY]

CHEM 241 UNIT 5: PART A DETERMINATION OF ORGANIC STRUCTURES BY SPECTROSCOPIC METHODS [MASS SPECTROMETRY] CHEM 241 UNIT 5: PART A DETERMINATION OF ORGANIC STRUCTURES BY SPECTROSCOPIC METHODS [MASS SPECTROMETRY] 1 Introduction Outline Mass spectrometry (MS) 2 INTRODUCTION The analysis of the outcome of a reaction

More information

(2) Read each statement carefully and pick the one that is incorrect in its information.

(2) Read each statement carefully and pick the one that is incorrect in its information. Organic Chemistry - Problem Drill 17: IR and Mass Spectra No. 1 of 10 1. Which statement about infrared spectroscopy is incorrect? (A) IR spectroscopy is a method of structure determination based on the

More information

Mass Spectrometry (MS)

Mass Spectrometry (MS) Kevin Burgess, February 20, 2017 1 Mass Spectrometry (MS) from chapter(s) in the recommended text A. Introduction Kevin Burgess, February 20, 2017 2 B. Components f Mass Spectrometers mass-to-charge. molecular

More information

Average Atomic Mass: How are the masses on the periodic table determined?

Average Atomic Mass: How are the masses on the periodic table determined? Chemistry Ms. Ye Name Date Block Average Atomic Mass: How are the masses on the periodic table determined? Most elements have more than one naturally occurring isotope. As you learned previously, the atoms

More information

Unit III: Quantitative Composition of Compounds

Unit III: Quantitative Composition of Compounds Unit III: Quantitative Composition of Compounds A. Atoms and Isotopes B. Atomic Composition of Chemical Compounds C. Formula and Molecular Mass D. Calculations using Moles of Atoms E. Calculations using

More information

ChemActivity L2: Mass Spectrometry

ChemActivity L2: Mass Spectrometry ChemActivity L2: Mass Spectrometry (How can we determine the mass and molecular formula of an unknown compound?) This activity is designed to be completed in a 1 ½-hour laboratory session or two classroom

More information

sample was a solution that was evaporated in the spectrometer (such as with ESI-MS) ions such as H +, Na +, K +, or NH 4

sample was a solution that was evaporated in the spectrometer (such as with ESI-MS) ions such as H +, Na +, K +, or NH 4 Introduction to Spectroscopy V: Mass Spectrometry Basic Theory: Unlike other forms of spectroscopy used in structure elucidation of organic molecules mass spectrometry does not involve absorption/emission

More information

Chemistry 101 Chapter 8 Chemical Composition

Chemistry 101 Chapter 8 Chemical Composition Chemistry 101 Chapter 8 Chemical Composition Atomic mass unit (amu): a unit of the scale relative masses of atoms (1 amu = 1.66 10-24 g). Atomic weight (Atomic mass): the atomic weight of an element given

More information

Atomic Structure. Atomic Notation. Atomic Notation. Atomic Notation. Section 3.3 Distinguishing Between Atoms. Atomic Notation

Atomic Structure. Atomic Notation. Atomic Notation. Atomic Notation. Section 3.3 Distinguishing Between Atoms. Atomic Notation Atomic Structure Section 3.3 Distinguishing Between Atoms OBJECTIVES: Explain how the atomic number identifies an element. Use the atomic number and mass number of an element to find the numbers of protons,

More information

Unit III: Quantitative Composition of Compounds

Unit III: Quantitative Composition of Compounds Unit III: Quantitative Composition of Compounds A. Atoms and Isotopes B. Atomic Composition of Chemical Compounds C. Formula and Molecular Mass D. Calculations using Moles of Atoms E. Calculations using

More information

NUCLEAR MAGNETIC RESONANCE AND INTRODUCTION TO MASS SPECTROMETRY

NUCLEAR MAGNETIC RESONANCE AND INTRODUCTION TO MASS SPECTROMETRY NUCLEAR MAGNETIC RESONANCE AND INTRODUCTION TO MASS SPECTROMETRY A STUDENT SHOULD BE ABLE TO: 1. Identify and explain the processes involved in proton ( 1 H) and carbon-13 ( 13 C) nuclear magnetic resonance

More information

ORGANIC - EGE 5E CH UV AND INFRARED MASS SPECTROMETRY

ORGANIC - EGE 5E CH UV AND INFRARED MASS SPECTROMETRY !! www.clutchprep.com CONCEPT: IR SPECTROSCOPY- FREQUENCIES There are specific absorption frequencies in the functional group region that we should be familiar with EXAMPLE: What are the major IR absorptions

More information

1 amu 1 amu 0 amu. Chapter 2 part 1.notebook September 16, Modern Atomic Theory

1 amu 1 amu 0 amu. Chapter 2 part 1.notebook September 16, Modern Atomic Theory Chapter 2 The Atom Elements are the basic substances that make up all matter. An atom is the smallest particle of an element. Average atoms are 10 10 m in diameter. If you could put 6.02 x 10 23 p + and

More information

ORGANIC - BRUICE 8E CH MASS SPECT AND INFRARED SPECTROSCOPY

ORGANIC - BRUICE 8E CH MASS SPECT AND INFRARED SPECTROSCOPY !! www.clutchprep.com CONCEPT: PURPOSE OF ANALYTICAL TECHNIQUES Classical Methods (Wet Chemistry): Chemists needed to run dozens of chemical reactions to determine the type of molecules in a compound.

More information

More information can be found in Chapter 12 in your textbook for CHEM 3750/ 3770 and on pages in your laboratory manual.

More information can be found in Chapter 12 in your textbook for CHEM 3750/ 3770 and on pages in your laboratory manual. CHEM 3780 rganic Chemistry II Infrared Spectroscopy and Mass Spectrometry Review More information can be found in Chapter 12 in your textbook for CHEM 3750/ 3770 and on pages 13-28 in your laboratory manual.

More information

Mass Spectroscopy. Dr. Sapna Gupta

Mass Spectroscopy. Dr. Sapna Gupta Mass Spectroscopy Dr. Sapna Gupta What is Mass Spectroscopy It is an analytical technique for measuring the mass-tocharge ratio (m/z) of ions in the gas phase. Mass spectrometry is our most valuable analytical

More information

What is a theory? An organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena

What is a theory? An organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena Atomic Structure What is a theory? An organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena Early Theories Democritus: 4 B.C.: atom He

More information

Chemistry 14C Winter 2017 Exam 2 Solutions Page 1

Chemistry 14C Winter 2017 Exam 2 Solutions Page 1 Chemistry 14C Winter 2017 Exam 2 Solutions Page 1 Statistics: High score, average, and low score will be posted on the course web site after exam grading is complete. Some questions have more than one

More information

Name AP CHEM / / Chapter 3 Outline Stoichiometry

Name AP CHEM / / Chapter 3 Outline Stoichiometry Name AP CHEM / / Chapter 3 Outline Stoichiometry Atomic Masses The modern system of atomic masses, instituted in 1961, is based on carbon-12. Carbon-12 is assigned the mass of exactly 12 atomic mass units

More information

The structure of the Atom. Chemistry chapter 4

The structure of the Atom. Chemistry chapter 4 The structure of the Atom Chemistry chapter 4 Rutherford-Bohr Model Niels Bohr (1922) Proposed improvements to Rutherford Atomic Model. For this reason the planetary model of the atoms is sometimes called

More information

Fri 6 Nov 09. More IR Mass spectroscopy. Hour exam 3 Fri Covers Chaps 9-12 Wednesday: Review

Fri 6 Nov 09. More IR Mass spectroscopy. Hour exam 3 Fri Covers Chaps 9-12 Wednesday: Review Fri 6 Nov 09 our exam 3 Fri 11-13 Covers Chaps 9-12 Wednesday: Review More IR Mass spectroscopy Good web site for IR, Mass, NMR spectra: http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng

More information

Practice Test Questions Chemistry Final Exam, May 24, 2016

Practice Test Questions Chemistry Final Exam, May 24, 2016 1 Practice Test Questions Chemistry Final Exam, May 24, 2016 Please note that this is not the format of the actual test. Answer the questions of this test to review your content knowledge. A. Atomic structure

More information

Topics in composition stoichiometry include the calculation of: Molar mass Percent Composition Molecular formula Empirical formulas

Topics in composition stoichiometry include the calculation of: Molar mass Percent Composition Molecular formula Empirical formulas Composition Stoichiometry Composition Stoichiometry NOTES 1 So far, we ve studied the products of a chemical reaction in terms of their identity. Stoichiometry is a branch of chemistry dealing with quantities.

More information

UNIT 2 - ATOMIC THEORY

UNIT 2 - ATOMIC THEORY UNIT 2 - ATOMIC THEORY VOCABULARY: Allotrope Electron Configuration Nuclear Charge Anion Element Nucleons Atom Excited state Nucleus Atomic Mass Ground state Orbital Atomic Mass unit (a.m.u.) Ion Proton

More information

Chapter 20. Mass Spectroscopy

Chapter 20. Mass Spectroscopy Chapter 20 Mass Spectroscopy Mass Spectrometry (MS) Mass spectrometry is a technique used for measuring the molecular weight and determining the molecular formula of an organic compound. Mass Spectrometry

More information

CHEMISTRY Topic #3: Using Spectroscopy to Identify Molecules: Radicals and Mass Spectrometry (MS) Spring 2018 Dr.

CHEMISTRY Topic #3: Using Spectroscopy to Identify Molecules: Radicals and Mass Spectrometry (MS) Spring 2018 Dr. CHEMISTRY 2600 Topic #3: Using Spectroscopy to Identify Molecules: Radicals and Mass Spectrometry (MS) Spring 2018 Dr. Susan Findlay Mass Spectrometry: How Does It Work? In CHEM 1000, you saw that mass

More information

UNIT 2 - ATOMIC THEORY

UNIT 2 - ATOMIC THEORY UNIT 2 - ATOMIC THEORY VOCABULARY: Allotrope Electron Configuration Nuclear Charge Anion Element Nucleons Atom Excited state Nucleus Atomic Mass Ground state Orbital Atomic Mass unit (a.m.u.) Ion Proton

More information

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT !! www.clutchprep.com CONCEPT: PURPOSE OF ANALYTICAL TECHNIQUES Classical Methods (Wet Chemistry): Chemists needed to run dozens of chemical reactions to determine the type of molecules in a compound.

More information

Chapter 20: Identification of Compounds

Chapter 20: Identification of Compounds Chemists are frequently faced with the problem of identifying unknown compounds. Environmental scientists may have to identify pollutants in soils and water, synthetic chemists may want to confirm that

More information

Structural Determination Of Compounds

Structural Determination Of Compounds EXPERIMENT 10 Mass Spectroscopy Structural Determination Of Compounds. Introduction - In mass spectrometry, a substance is bombarded with an electron beam having sufficient energy to fragment the molecule.

More information

Chapter 2: Atoms and Molecules

Chapter 2: Atoms and Molecules SYMBOLS AND FORMULAS A unique symbol is used to represent each element. Formulas are used to represent compounds. Chapter 2: Atoms and Molecules ELEMENTAL SYMBOLS A symbol is assigned to each element.

More information

Identifying Functional Groups. Why is this necessary? Alkanes. Why is this so important? What is a functional group? 2/1/16

Identifying Functional Groups. Why is this necessary? Alkanes. Why is this so important? What is a functional group? 2/1/16 Identifying Functional Groups The Key to Survival Why is this so important? ver and over again, you will be asked to do reactions, the details to which you will receive in lecture and via your textbook.

More information

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT !! www.clutchprep.com CONCEPT: PURPOSE OF ANALYTICAL TECHNIQUES Classical Methods (Wet Chemistry): Chemists needed to run dozens of chemical reactions to determine the type of molecules in a compound.

More information

Chapter No. 1 BASIC CONCEPTS Short Question With Answer Q.1 Calculate the grams atoms in 0.4 gm of potassium. Gram atoms of potassium = = = 0.01 grams atoms Q.2 23 grams of sodium and 238 gram of uranium

More information

Topic 02 Atomic Structure 2.2: The Mass Spectrometer. IB Chemistry T02D02

Topic 02 Atomic Structure 2.2: The Mass Spectrometer. IB Chemistry T02D02 Topic 02 Atomic Structure 2.2: The Mass Spectrometer IB Chemistry T02D02 2.1 The Mass Spectrometer - 1 hour 2.2.1 Describe and explain the operation of a mass spectrometer. (3) 2.2.2 Describe how the mass

More information

Experiment 2 - NMR Spectroscopy

Experiment 2 - NMR Spectroscopy Experiment 2 - NMR Spectroscopy OBJECTIVE to understand the important role of nuclear magnetic resonance spectroscopy in the study of the structures of organic compounds to develop an understanding of

More information

Chapter 3. Mass Relationships in Chemical Reactions

Chapter 3. Mass Relationships in Chemical Reactions Chapter 3 Mass Relationships in Chemical Reactions In this chapter, Chemical structure and formulas in studying the mass relationships of atoms and molecules. To explain the composition of compounds and

More information

UNIT 2 - ATOMIC THEORY

UNIT 2 - ATOMIC THEORY UNIT 2 - ATOMIC THEORY VOCABULARY: Allotrope Anion Atom Atomic Mass Atomic Mass unit (a.m.u.) Atomic number Bohr model Cation Compound Electron Electron Configuration Element Excited state Ground state

More information

Paper 12: Organic Spectroscopy

Paper 12: Organic Spectroscopy Subject Chemistry Paper No and Title Module No and Title Module Tag Paper 12: Organic Spectroscopy 31: Combined problem on UV, IR, 1 H NMR, 13 C NMR and Mass - Part III CHE_P12_M31 TABLE OF CONTENTS 1.

More information

Big Idea #1 : Atomic Structure

Big Idea #1 : Atomic Structure The chemical elements are fundamental building materials of matter, and all matter can be understood in terms of arrangements of atoms. These atoms retain their identity in chemical reactions. Big Idea

More information

Mass Spectrometry. Introduction EI-MS and CI-MS Molecular mass & formulas Principles of fragmentation Fragmentation patterns Isotopic effects

Mass Spectrometry. Introduction EI-MS and CI-MS Molecular mass & formulas Principles of fragmentation Fragmentation patterns Isotopic effects Mass Spectrometry Introduction EI-MS and CI-MS Molecular mass & formulas Principles of fragmentation Fragmentation patterns Isotopic effects 1 Introduction to MS Mass spectrometry is the method of analysis

More information

7. How many moles of hydrogen sulfide are contained in a 35.0-g sample of this gas? [A] 2.16 mol [B] 7.43 mol [C] 6.97 mol [D] 10.4 mol [E] 1.

7. How many moles of hydrogen sulfide are contained in a 35.0-g sample of this gas? [A] 2.16 mol [B] 7.43 mol [C] 6.97 mol [D] 10.4 mol [E] 1. 1. Bromine exists naturally as a mixture of bromine-79 and bromine-81 isotopes. An atom of bromine-79 contains [A] 35 protons, 44 neutrons, 35 electrons. [B] 79 protons, 79 electrons, and 35 neutrons.

More information

Mass spectrometry and elemental analysis

Mass spectrometry and elemental analysis Mass spectrometry and elemental analysis A schematic representation of a single-focusing mass spectrometer with an electron-impact (EI) ionization source. M: + e _ M +. + 2e _ Ionization and fragmentation

More information

How do Elements Combine to Form Compounds?

How do Elements Combine to Form Compounds? How do Elements Combine to Form Compounds? ACTIVITY What is it made of? Compounds account for the huge variety of matter on Earth All the compounds that exist on Earth are built from elements 118 elements

More information

Welcome to Organic Chemistry II

Welcome to Organic Chemistry II Welcome to Organic Chemistry II Erika Bryant, Ph.D. erika.bryant@hccs.edu Class Syllabus 3 CHAPTER 12: STRUCTURE DETERMINATION 4 What is this solution Soda Tea Coffee??? 5 What is this solution Soda Tea

More information

Reminder: My Office Hours HELD 104A & CHEM 330. Instructional Assistant (IA)

Reminder: My Office Hours HELD 104A & CHEM 330. Instructional Assistant (IA) Reminder: My Office Hours HELD 104A & CHEM 330 Tuesdays & Thursdays, 4:00-5:30 (That s the 90 min. before each class) in HELD 104A. Fridays, 1:30-3:00 in CHEM 330 Other times as available or by appointment.

More information

Unit 6 Chemical Analysis. Chapter 8

Unit 6 Chemical Analysis. Chapter 8 Unit 6 Chemical Analysis Chapter 8 Objectives 39 Perform calculations using the mole to calculate the molar mass 40 Perform calculations using the mole to convert between grams, number of particles, volume,

More information

PERCENTAGE COMPOSITION

PERCENTAGE COMPOSITION PERCENTAGE COMPOSITION Just like any percentage problems you are comparing the part to the whole. In chemistry, percentage composition is based on mass, not on numbers of atoms present. For Example, if

More information

CHEM Chapter 12 Infrared and Mass Spec (homework). Stafford. S18

CHEM Chapter 12 Infrared and Mass Spec (homework). Stafford. S18 Exhibit 12-4 The following question(s) refer to the mass spectrum shown below. 1. Refer to Exhibit 12-4. This compound contains C, H, and one other atom. Identify the other atom from the mass spectrum

More information

MATTER AND ITS PROPERTIES

MATTER AND ITS PROPERTIES FINAL REVIEW MATTER AND ITS PROPERTIES VIDEO ATOM Smallest unit of an element that maintains the chemical identity of that element. ELEMENT A pure substance that cannot be broken down into simpler, stable

More information

Isotopes...do on index card

Isotopes...do on index card Electrons and Ions Isotopes...do on index card Carbon-12 accounts for 99.45% of all of the carbon atoms, while carbon-14 only accounts for the remaining 0.55%. Since the carbon-12 isotope is more abundant,

More information

Instructional Assistant (IA) Reminder: My Office Hours HELD 104A & CHEM 330. Supplemental Instruction (SI) Homework update. Matter, Atoms & Molecules

Instructional Assistant (IA) Reminder: My Office Hours HELD 104A & CHEM 330. Supplemental Instruction (SI) Homework update. Matter, Atoms & Molecules Reminder: My Office ours ELD 104A & CEM 330 Tuesdays & Thursdays, 4:00-5:30 (That s the 90 min. before each class) in ELD 104A. Fridays, 1:30-3:00 in CEM 330 Other times as available or by appointment.

More information

Interpretation of Organic Spectra. Chem 4361/8361

Interpretation of Organic Spectra. Chem 4361/8361 Interpretation of Organic Spectra Chem 4361/8361 Characteristics of Common Spectrometric Methods H-1 C-13 MS IR/RAMAN UV-VIS ORD/CD X- RAY Radiation type RF RF Not relevant IR UV to visible UV to visible

More information

Chem 110 Fall 2014 Exam I Whelan

Chem 110 Fall 2014 Exam I Whelan Chem 110 Fall 2014 Exam I Whelan SID Last First Question 1 5 Points a) How many significant figures are there in each of the following numbers? 0.927790 0.060464 1.00x10 3 b) There are 12 eggs in a dozen.

More information

EXAM 1 Review Session

EXAM 1 Review Session EXAM 1 Review Session DR. MIOY T. HUYNH YALE UNIVERSITY CHEMISTRY 161 FALL 2018 www.mioy.org/chem161 OUTLINE 1. Significant Figures 2. Dimensional Analysis 3. Elements and Atoms 4. Naming Compounds 5.

More information

CHAPTER 4. Atomic Structure. 4.1 Atoms. Dalton s Atomic Theory

CHAPTER 4. Atomic Structure. 4.1 Atoms. Dalton s Atomic Theory CHAPTER 4 Atomic Structure 4.1 Atoms Democritus first suggested the idea of atoms Indivisible & Indestructible 460 B.C. 370 B.C. Dalton s Atomic Theory 1. All elements are composed of submicroscopic indivisible

More information

Atomic Number. Mass Number. Counting Subatomic Particles

Atomic Number. Mass Number. Counting Subatomic Particles Counting Subatomic Particles Now that scientists have discovered that atoms can be subdivided into subatomic particles, there was a new problem. How do we count subatomic particles? We use terms like atomic

More information

Average Atomic Mass. A new unit called the atomic mass unit (amu) was developed to deal with the very small units of mass for particles like the atom.

Average Atomic Mass. A new unit called the atomic mass unit (amu) was developed to deal with the very small units of mass for particles like the atom. Average Atomic Mass Since atoms are so small and the mass of individual atoms is also very small, it is not useful to use the units of grams or kilogram. A new unit called the atomic mass unit (amu) was

More information

Get out a sheet of paper to take some notes on.

Get out a sheet of paper to take some notes on. Bellwork: Get out your old textbook and your ID. Get out a sheet of paper to take some notes on. Solve the following problem. Methyl alcohol, CH 3 OH, is a clean-burning, easily handled fuel. It can be

More information

Introductory Chemistry: A Foundation, 6 th Ed. Introductory Chemistry, 6 th Ed. Basic Chemistry, 6 th Ed.

Introductory Chemistry: A Foundation, 6 th Ed. Introductory Chemistry, 6 th Ed. Basic Chemistry, 6 th Ed. Introductory Chemistry: A Foundation, 6 th Ed. Introductory Chemistry, 6 th Ed. Basic Chemistry, 6 th Ed. by Steven S. Zumdahl & Donald J. DeCoste University of Illinois Chapter 8 Chemical Composition

More information

In a solution, there are thousands of atoms generating magnetic fields, all in random directions.

In a solution, there are thousands of atoms generating magnetic fields, all in random directions. Nuclear Magnetic Resonance Spectroscopy: Purpose: onnectivity, Map of - framework Process: In nuclear magnetic resonance spectroscopy, we are studying nuclei. onsider this circle to represent a nucleus

More information

1. Predict the structure of the molecules given by the following spectral data: a Mass spectrum:m + = 116

1. Predict the structure of the molecules given by the following spectral data: a Mass spectrum:m + = 116 Additional Problems for practice.. Predict the structure of the molecules given by the following spectral data: a Mass spectrum:m + = IR: weak absorption at 9 cm - medium absorption at cm - NMR 7 3 3 C

More information

UNIT 2 - ATOMIC THEORY

UNIT 2 - ATOMIC THEORY *KEY* *KEY* UNIT 2 - ATOMIC THEORY *KEY* *KEY* VOCABULARY: Allotrope Anion Atom Atomic Mass Atomic Mass unit (a.m.u.) Atomic number Bohr model Cation Compound Electron Electron Configuration Element Excited

More information

Intro to Chemistry and Physics/Pre-AP Chem UNIT 2 Atoms: The Building Blocks of Matter 2:1 Foundations of Atomic Theory

Intro to Chemistry and Physics/Pre-AP Chem UNIT 2 Atoms: The Building Blocks of Matter 2:1 Foundations of Atomic Theory 2:1 Foundations of Atomic Theory In the 1790s the study of matter was revolutionized by the quantitative analysis of chemical reactions, which had been greatly improved by more accurate balances. This

More information

CH Exam #4 (Take Home) Date Due: 11/25,26/2013

CH Exam #4 (Take Home) Date Due: 11/25,26/2013 CH2710 - Exam #4 (Take Home) Date Due: 11/25,26/2013 Section I - Multiple Choice - Choose the BEST answer from the choices given and place the letter of you choice in the space provided. 1. Energy absorbed

More information

Mass Spectrometry - Background

Mass Spectrometry - Background Mass Spectrometry - Background In mass spectrometry, a substance is bombarded with an electron beam having sufficient energy to fragment the molecule. The positive fragments which are produced (cations

More information

General Chemistry. Chapter 3. Mass Relationships in Chemical Reactions CHEM 101 (3+1+0) Dr. Mohamed El-Newehy 10/12/2017

General Chemistry. Chapter 3. Mass Relationships in Chemical Reactions CHEM 101 (3+1+0) Dr. Mohamed El-Newehy 10/12/2017 General Chemistry CHEM 101 (3+1+0) Dr. Mohamed El-Newehy http://fac.ksu.edu.sa/melnewehy Chapter 3 Mass Relationships in Chemical Reactions 1 In this chapter, Chemical structure and formulas in studying

More information

CP/Honors Chemistry Unit 3: Atomic Theory Chapter 4, Sections 1, 2, and 3

CP/Honors Chemistry Unit 3: Atomic Theory Chapter 4, Sections 1, 2, and 3 CP/Honors Chemistry Unit 3: Atomic Theory Chapter 4, Sections 1, 2, and 3 Subatomic Particles Warm-Up Quiz 1. What are the three subatomic particles? 2. Where are the particles located in the atom? 3.

More information

Notes:&&Unit&4:&Atomics& & & & & & & & & & & & & & & & &

Notes:&&Unit&4:&Atomics& & & & & & & & & & & & & & & & & Name: RegentsChemistry:Mr.Palermo Notes:Unit4:Atomics! www.mrpalermo.com Name: $ Key$Ideas$ Themodernmodeloftheatomhasevolvedoveralongperiodoftimethroughtheworkofmany scientists.(3.1a) Eachatomhasanucleus,withanoverallpositivecharge,surroundedbyoneormorenegatively

More information

Mole Concept. Conversion Factors:

Mole Concept. Conversion Factors: Today s focus. Mole Concept Avogadro s Number is 6.02x10 23 The mole unit is used to express: 1. A mass quantity 2. A counting quantity 1 water molecule 1 mole of water molecules Conversion Factors: 6.02x10

More information

POGIL: Average Atomic Mass

POGIL: Average Atomic Mass Name: Date: Period: Chemistry POGIL: Average Atomic Mass WHY? It is assumed that the composition of a sample of an element (in terms of percent natural abundances of each of the element s isotopes) is

More information

CHEM311 FALL 2005 Practice Exam #3

CHEM311 FALL 2005 Practice Exam #3 CHEM311 FALL 2005 Practice Exam #3 Instructions: This is a multiple choice / short answer practice exam. For the multiple-choice questions, there may be more than one correct answer. If so, then circle

More information

Atoms, Molecules, and the Mole

Atoms, Molecules, and the Mole The Mole Now that we know how to write and name chemical compounds, we need to understand how chemists use these formulas quantitatively. As chemists, we need to know how many atoms or molecules are reacting

More information

Atomic Structure Early Theories Democritus: 4 B.C.: atom Dalton: atoms cannot Thomson: Cathode Ray Tubes Rutherford:

Atomic Structure Early Theories Democritus: 4 B.C.: atom Dalton: atoms cannot Thomson: Cathode Ray Tubes Rutherford: Atomic Structure n a well-substantiated explanation of some aspect of the natural world; n an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set

More information

4. Draw a concept map showing the classifications of matter. Give an example of each.

4. Draw a concept map showing the classifications of matter. Give an example of each. Name Bring calculator, pencils, and this completed worksheet to the midterm exam. For problems involving an equation, carry out the following steps: 1. Write the equation. 2. Substitute numbers and units.

More information

Nuclear Magnetic Resonance Spectroscopy: Purpose: Connectivity, Map of C-H framework

Nuclear Magnetic Resonance Spectroscopy: Purpose: Connectivity, Map of C-H framework Nuclear Magnetic Resonance Spectroscopy: Purpose: Connectivity, Map of C- framework Four Factors of Proton NMR (PMR OR NMR):. Symmetry: Number of chemically different protons (symmetry) as shown by number

More information

2. Separate the ions based on their mass to charge (m/e) ratio. 3. Measure the relative abundance of the ions that are produced

2. Separate the ions based on their mass to charge (m/e) ratio. 3. Measure the relative abundance of the ions that are produced I. Mass spectrometry: capable of providing both quantitative and qualitative information about samples as small as 100 pg (!) and with molar masses in the 10 4-10 5 kdalton range A. The mass spectrometer

More information

Unit 2: Essentials of Chemistry Homework Packet (80 points)

Unit 2: Essentials of Chemistry Homework Packet (80 points) Name: KEY Period: By the end of Unit 2, you should be able to: Essentials of Chemistry Chapter 1-2 & 4-5 Unit 2: Essentials of Chemistry 8. Explain the nature of science including the use of the validity

More information

6 atomic # C symbol Carbon name of element atomic mass. o Examples: # 1 mol C = g # 1 mol O = g # 1 mol H = 1.

6 atomic # C symbol Carbon name of element atomic mass. o Examples: # 1 mol C = g # 1 mol O = g # 1 mol H = 1. 7.1 AVOGADRO S NUMBER AND MOLAR CONVERSIONS CHEMISTRY NOTES Identify the mole as the unit used to count particles, whether atoms, ions, or molecules. Use Avogadro s number to convert between amount in

More information

Practice Test 1 Bio 103 Name

Practice Test 1 Bio 103 Name Practice Test 1 Bio 103 Name 1) An atom with an atomic number of 9 and a mass number of 19 would have an atomic mass of approximately? a) 10 Daltons b) 19 Daltons c) 9 grams d) 9 Daltons e) 20 grams 2)

More information

Atomic Structure. What is an atom? The smallest particle of an element that retains properties of that element. Gedanken

Atomic Structure. What is an atom? The smallest particle of an element that retains properties of that element. Gedanken Atomic Structure What is an atom? The smallest particle of an element that retains properties of that element. Gedanken 1 Atomic Theory Democritus vs. Dalton 500 BC 1808 AD Pure thought Observation + experiment

More information

1. Which of the following compounds is the weakest base?

1. Which of the following compounds is the weakest base? I. Multiple-choice Questions Fall 2018 1. Which of the following compounds is the weakest base? a. C3C2 b. C3C2 c. N3 d. C3 e. N2 2. Which of the following functional groups is indicated by a strong and

More information

How many hydrogen atoms are there in the empirical formula of propene, C 3 H 6? How many neutrons are there in one atom of 24 Mg?

How many hydrogen atoms are there in the empirical formula of propene, C 3 H 6? How many neutrons are there in one atom of 24 Mg? 1 A 2 B 3 C The atomic number of Na is 11. How many electrons are there in a sodium ion, Na +? How many hydrogen atoms are there in the empirical formula of propene, C 3 H 6? What is the mass in grams

More information

THE STRUCTURE OF ATOMS. ATOMS Atoms consist of a number of fundamental particles, the most important are... in the nucleus of an atom

THE STRUCTURE OF ATOMS. ATOMS Atoms consist of a number of fundamental particles, the most important are... in the nucleus of an atom Atomic Structure TE STRUCTURE OF ATOMS ATOMS Atoms consist of a number of fundamental particles, the most important are... Mass / kg Charge / C Relative mass Relative Charge PROTON NEUTRON ELECTRON MASS

More information

Chapter 12 Mass Spectrometry and Infrared Spectroscopy

Chapter 12 Mass Spectrometry and Infrared Spectroscopy Organic Chemistry, 6 th Edition L. G. Wade, Jr. Chapter 12 Mass Spectrometry and Infrared Spectroscopy Jo Blackburn Richland College, Dallas, TX Dallas County Community College District 2006, Prentice

More information

Name: 1. Ignoring C-H absorptions, what characteristic IR absorption(s) would be expected for the functional group shown below?

Name: 1. Ignoring C-H absorptions, what characteristic IR absorption(s) would be expected for the functional group shown below? Chemistry 262 Winter 2018 Exam 3 Practice The following practice contains 20 questions. Thursday s 90 exam will also contain 20 similar questions, valued at 4 points/question. There will also be 2 unknown

More information

MASS SPECTROSCOPY (MS)

MASS SPECTROSCOPY (MS) MASS SPECTOSCOPY (MS) Castor seeds icin (toxic protein) INTODUCTION Does not involve absorption of electromagnetic radiation. It is a spectroscopic technique, by virtue of its use in structure elucidation.

More information

Chem 14C Lecture 1 Spring 2016 Exam 2 Solutions Page 1

Chem 14C Lecture 1 Spring 2016 Exam 2 Solutions Page 1 Chem 14C Lecture 1 Spring 2016 Exam 2 Solutions Page 1 Statistics: High score, average, and low score will be posted on the course web site after exam grading is complete. Some questions have more than

More information

CLASS SET DO NOT WRITE. Beanium Isotope Lab

CLASS SET DO NOT WRITE. Beanium Isotope Lab CLASS SET DO NOT WRITE Beanium Isotope Lab Introduction & Purpose: What is an isotope? What does it mean to say that the atoms in a sample of an element are isotopes of each other? Ordinary beans are a

More information

How do Elements Combine to Form Compounds?

How do Elements Combine to Form Compounds? How do Elements Combine to Form Compounds? ACTIVITY What is it made of? Think about the calcium atom vs the calcium ion Compounds account for the huge variety of matter on Earth All the compounds that

More information

STOICHIOMETRY EXAM TRUTH! Thursday & Friday 10/01-10/02/2015. Friday, October 2, 15

STOICHIOMETRY EXAM TRUTH! Thursday & Friday 10/01-10/02/2015. Friday, October 2, 15 STOICHIOMETRY EXAM Thursday & Friday 10/01-10/02/2015 TRUTH! AGENDA Finish Stoichiometry Unit Exam (45 minutes MAX) Begin Topic 2: Atomic Structure & Project Introduction Groups assigned today GROUPS You

More information

Activity # 2. Name. Date due. Assignment on Atomic Structure

Activity # 2. Name. Date due. Assignment on Atomic Structure Activity # 2 10 Name Date Date due Assignment on Atomic Structure NOTE: This assignment is based on material on the Power Point called Atomic Structure, as well as pages 167-173 in the Science Probe textbook.

More information

[3.2] The Atom. p in Textbook

[3.2] The Atom. p in Textbook [3.2] The Atom p. 145 149 in Textbook We will be learning about three different parts of the atom today 1. What makes up an atom 2. Where an atom s mass is found 3. What are isotopes What does the atom

More information

Early Atomic Models. Atoms: the smallest particle of an element that retains the properties of that element.

Early Atomic Models. Atoms: the smallest particle of an element that retains the properties of that element. Chapter 5 Early Atomic Models Atoms: the smallest particle of an element that retains the properties of that element. (Greek: atomos = indivisible) Democritus (Greek teacher in the 4 th century BC) First

More information

MS Interpretation I. Identification of the Molecular Ion

MS Interpretation I. Identification of the Molecular Ion MS Interpretation I Identification of the Molecular Ion Molecular Ion: EI Requirements for the Molecular Ion Must be the highest m/z peak in the spectrum Highest Isotope Cluster Must be an odd-electron

More information

What is the energy of a photon with wavelength 232 nm?

What is the energy of a photon with wavelength 232 nm? EMISTRY 110 EXAM 1 February 6, 2012 FRM A 1 ow many single covalent bonds must a sulfur atom form to have a complete octet in its valence shell? A. 3 B. 4. 1 D. 2 E. 0 2. What are the correct numbers of

More information

Unit 2 Chapters 5 and 6 Atoms/Periodic Table/ NOMENCLATURE NAMING AND FORMING COMPOUNDS

Unit 2 Chapters 5 and 6 Atoms/Periodic Table/ NOMENCLATURE NAMING AND FORMING COMPOUNDS Unit 2 Chapters 5 and 6 Atoms/Periodic Table/ NOMENCLATURE NAMING AND FORMING COMPOUNDS Review of Atomic Structure What is an atom? The smallest particle of an element that retains the properties of that

More information