Syllabus Chemistry 101 Fall 2009 Sec. 501 (MWF 8:00-8:50) Sec 505 (MWF 12:40-1:30) RM 100 HELD Professor: Dr. Earle G. Stone Office: Room 123E Heldenfels (HELD) Telephone: 845-3010 (no voice mail) or leave a message at 845-2356 email: firstname.lastname@example.org (put CHEM 101-Sec. # + subject in subject line of your email) Office Hours: HELD 123E: Tue. And Thur. 8:00-10:50 AM I.A. TBA S.I. Leader: TBA CHEM 101 and 102 are the first-year chemistry sequence in the core curriculum. These are 3-credit courses. All lecture sections strive to cover common content. The lecture component of Chemistry 101 covers stoichiometry, atomic and molecular structure, chemical bonding, fundamental acid/base chemistry, solution chemistry, properties of liquids and solids, the gas laws, and this class will additionally cover foundation work in inorganic and organic nomenclature and structure, including some mention of major biological organic and inorganic compounds. More importantly, it is the goal of my lecture section to help you develop the skill set to successfully complete your undergraduate degree and as most in this class are pre-something to prepare for your professional school entrance exam and enable you to succeed in your choice of professional school.
Kotz and Treichel 7th ed. TEXTBOOKS Averill and Eldridge Helpful Online Dictionary of Chemistry Useful As A Second Language General Chemistry I and Organic Chemistry I (There are O-chem II and Physics books in this series if you find these useful and will have to take those classes. • Hardbound ~$200 • Solution Manual ~$40 • Online Tutor ~$45 • Total ~$285 • Ebook $45 per semester • Includes • Text • Solution manual • Online tutorial Yvette Freeman Publisher's Representative Pearson Education Chang’s Essentials
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Grading: • Your grade will be based on • Four one-hour examinations (each worth 200 points) • A final examination (400 points) • There are no bonuses, no extra credit, no soft points • Major Examination Schedule Fall 2005: • Wed. Sept. 16 Major Exam No.1 • Wed. Oct. 7 Major Exam No.2 • Mon. Nov. 9 Major Exam No.3 • Fri. Dec. 4 Major Exam No. 4 • Fri. Dec. 11 Section 501 Final Exam 10:00 to 12:00 • Mon. Dec. 14 Section 506 Final Exam 10:30 to 12:30
How grades are determined The way the real world works Individual Mastery compared to a large population What you are used to and I will report 1) Raw scores are determined. Sum of points assigned to correct responses 2) Individual scores are normalized. A context-free evaluation of relative performance 3) Normalized scores are transformed. An absolute score is assigned to a defined scale 4) Letter grades are assigned>89.451 A >79.451 B >69.451 C >59.451 D <59.451 F
And we begin: • Problem - A situation that presents difficulty, uncertainty, or perplexity: • The mere formulation of a problem is far more often essential than its solution, which may be merely a matter of mathematical or experimental skill. To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks real advances in science. ~Albert Einstein • Question - A request for data: inquiry, • interrogation, query. • Answer - A spoken or written reply, as to • a question. • Solution - Something worked out to explain, • resolve, or provide a method for • dealing with and settling a problem.
Scientific Method - A procedure that searches for answers to questions and solutions to problems, which consists of: http://museum.nist.gov/exhibits/adx2/index.htm http://www.batteryequaliser.com/behome.html http://museum.nist.gov/exhibits/adx2/index.htm http://www.patentstorm.us/patents/5945236-description.html
Observations • Can be qualitative or quantitative • Qualitative observations describe properties or occurrences in ways that do not rely on numbers. • Quantitative observations are measurements that consist of a number a unit and a label Hypotheses • A tentative explanation for the observations that may not be correct, but puts the scientist’s understanding of the system being studied into a form that can be tested Experiments • Tests the validity of the hypothesis • Are systematic observations or measurements made under controlled conditions, in which the variable of interest is clearly distinguished from any others • If experimental results are reproducible, they are summarized in a law. Law • A verbal or mathematical description of a phenomenon that allows for general predictions that describes what happens and not why and is unlikely to change greatly over time unless a major experimental error is discovered. • Attempts to explain why nature behaves as it does which is incomplete and imperfect and evolves with time to explain new facts as they are discovered Theory
Natural Laws • Law of Conservation of Mass – The notion that mass, or matter, can be neither created nor destroyed. • Law of Conservation of Energy – A law that states that in any system not involving nuclear reactions or velocities approaching the velocity of light, energy cannot be created or destroyed. The First Law of Thermodynamics. • Law of Conservation of Mass – Energy – Einstein’s General Theory of Relativity - E=mc2 – with work becomes the special theory of relativity, which has been verified by experiment, has shown that the mass of a body changes as the energy possessed by the body changes. Such changes in mass are too small to be detected except in subatomic phenomena. Matter may be created by the materialization of a photon into an electron-positron pair; or it may be destroyed, by the annihilation of this pair of elementary particles to produce a pair of photons.
Natural Laws Law of Definite Proportions – When two or more elements combine to form a compound, their masses in that compound are in a fixed and definite ratio. This data helps justify an atomic view of matter. Law of Multiple Proportions – When two elements combine to form more than one compound, the mass of element A which combines in the first compound with a given amount of element B has a simple whole number ratio with the mass of element A which combines in the second compound with the same given mass of element B.
Dr. Stone’s patent pending chemistry problem solver • Write down everything you are given • Vocabulary • Numbers • Units • Write down what you want to know • Vocabulary • Numbers • Units • Write down mathematical equation(s) that include(s) these values and units • Principles • Write a balanced stoichiometric equation • Mole concept • Convert everything to moles • Dimensionalanalysis • Convert everything to the unknown’s units • Rounding, significant figures, accuracy and precision
c (ms-1) l (m) • Numbers –Significant Figures, Rounding Rules, Accuracy, Precision, Statistical Treatment of the Data • Units – 1. Density? • 2. Molecular Weight (Mass) • 3. Mole Ratio, Molarity, molality • Vocabulary – Approximately 100 new terms or words and applying new or more rigid definitions to words you may already own. • Principles (Theories and Laws) – Mathematical formulas are used to model observed phenomena to predict possible outcomes - Stoichiometry, Quantum Theory, Bonding, Chemical Periodicity, Solutions, Thermodynamics, Intermolecular Forces, Gas Laws • cp = q/mDT rate = k[A]m[B]n ∆E = q + w • DG = DH – TDS Eocell = Ecathode = Eanode • PV = nRT %yield = actual/theoretical * 100% K = • DT = Kmi [C]c[D]d [A]a[D]b E = n =
Use of Numbers • Exact numbers • 1 dozen = 12 things for example • Accuracy • how closely measured values agree with the correct value • Precision • how closely individual measurements agree with each other • Significant Figures – start at the left and proceed to the right • If the number does not have a decimal point count until there are no more non zero numbers • If the number has a decimal point start counting at the first non-zero number and continue counting until you run out of decimal places • Scientific notation – use it.
Use of Numbers • Multiplication & Division rule • Easier of the two rules • Product has the smallest number of significant figures of multipliers • Addition & Subtraction rule More subtle than the multiplication rule Answer contains smallest decimal place of the addends. When a 5 appears. Is there anything to the right of the 5 greater than zero? Is the number to the left of the 5 odd? Is the number to the left of the 5 even? (Treat 0 as even.)
Use of Numbers How many sig figs? 0.0713200 7843000 1.4800 100 100.0 894.003 89400 0.03000 74.000 How many sig figs in the answer? 472x101 4600x0.005 36.0x4752 45.08/36.2 1.003/8500 0.003/472x12 3.003/475.0x0.30/524 0.3005x4.1 23.56+24.983 4.78-2.892 46.83-0.03 34.892+5.0 134.033-0.02 48.2-46 Round off to two sig figs 34.78 17.51 48.50 45.50001 24.33 17.50 20.5 45.5000 ] [ 23.56 – 2.3 = (1.68) 1.248 x 103
Vocabulary • Chemistry- Science that describes matter – its properties-composition-structure, the changes it undergoes, and the energy changes that accompany those processes • Matter - Anything that has mass and occupies space. • Energy -The capacity to do work or transfer heat. • Chemical Properties - chemical changes - describes the characteristic ability of a substance to react to form new substances (flammability and corrosion). • rusting or oxidation, chemical reactions • Physical Properties - physical changes - Characteristics that scientists can measure without changing the composition of the sample under study (mass, color, volume, amount of space occupied by the sample). • changes of state, density, color, solubility • Extensive Properties - depend on quantity a. Vary with the amount of the substance b. Include mass, weight, and volume. • Intensive Properties - do not depend on quantity a. Include color, melting and boiling point, electrical conductivity, and physical state at a given temperature b. Determine a substance’s identity, c. Have an important intensive property called density (d), a ratio of two extensive properties, mass and volume density = mass d = m volume V
Vocabulary • Three distinct states of matter: • 1. Solids — relatively rigid and have fixed shapes and volumes • — volumes of solids independent of temperature and pressure • 2. Liquids — have fixed volumes but flow to assume the shape of their containers • — Volumes of liquids independent of temperature and pressure • 3. Gases — have neither fixed shapes nor fixed volumes and expand to fill their containers completely • — Depends strongly on temperature and pressure
Vocabulary –Isotopes and Atomic Masses • Atoms of different elements exhibit different chemical behavior. • Identity of an element is defined by its atomic number. • (Z) is the number of protons in the nucleus of an atom of the element. • The atomic number is therefore different for each element. • Known elements are arranged in order of increasing Z in the periodic table.
Vocabulary –Isotopes and Atomic Masses • The chemistry of each element is determined by its number of protons and electrons. • In a neutral atom, the number of electrons equals the number of protons. • Symbols for elements are derived directly from the element’s name. • Nuclei of atoms contain neutrons as well as protons. • The number of neutrons is not fixed for most elements, unlike protons. • Atoms that have the same number of protons, and hence the same atomic number, but different numbers of neutrons are called isotopes. • Isotopes - All isotopes of an element have the same number of protons and electrons, which means they exhibit the same chemistry. Isotopes of an element differ only in their atomic mass.
Vocabulary –Isotopes and Atomic Masses • Atomic mass 1. The mass of any given atom is not simply the sum of the masses of its electrons, protons, and neutrons. 2. Atoms are too small to measure individually and do not have a charge. 3. The arbitrary standard that has been established for describing atomic mass is the atomic mass unit (amu), defined as one-twelfth of the mass of one atom of 12C. 4. Most elements exist as mixtures of several stable isotopes. The weighted average is of the masses of the isotopes is called the atomic mass. 5. Electrons added or removed from an atom produce a charged particle called an ion, whose charge is indicated by a superscript after the symbol for the element.
Vocabulary –Essential Elements • Elements that are absolutely required in the diets of humans are called essential elements (highlighted in purple). • Essential elements are restricted to the first four rows of the periodic table with only two exceptions (Mo and ). • An essential element is one that is required for life and whose absence results in death. • An element is considered to be essential if a deficiency consistently causes abnormal development or functioning and if dietary supplementation of that element and only that element prevents this adverse effect.
Classification of the Essential Elements • Most living matter consists primarily of bulk elements—oxygen, carbon, hydrogen, nitrogen, and sulfur. They are the building blocks of the compounds that make up our organs and muscles; they also constitute the bulk of our diet. • Six elements—sodium, magnesium, potassium, calcium, chlorine, and phosphorus—are called macrominerals and provide essential ions in body fluids and form the major structural components of the body. • Remaining essential elements called trace elements and are present in small amounts.
The Trace Elements • It is difficult to detect low levels of some of the essential elements, so the trace elements were relatively slow to be recognized. • Many compounds of trace elements are toxic. • Dietary intakes of elements range from deficient to optimum to toxic with increasing quantities; the optimum levels differ greatly for the essential elements.
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Chemical Compounds Atoms in all substances that contain more than one atom are held together by electrostatic interactions—interactions between electrically charged particles such as protons and electrons.
Compounds & Molecules • COMPOUNDS are a combination of 2 or more elements in definite ratios by mass. (Law of Definite Proportions) • The character of each element is lost when forming a compound. • MOLECULES are the smallest unit of a compound that retains the characteristics of the compound. • The composition of molecular compounds is given by a • CHEMICAL FORMULA
WRITING FORMULAS Chemical Formula – chemical symbols and number of each representing composition Empirical Formula – simplest ratio of elements that does not represent the actual number and is non-positional Molecular Formula – chemical symbols and number of each representing composition representing actual number but not position Structural Formula – chemical symbols and number of each representing composition representing actual number and position The structural chemical formula for glycine can be written as H2NCH2COOH to show atom ordering or in the bond-line structural formula Enables chemists to create a three-dimensional model that provides information about the physical and chemical properties of the compound
WRITING FORMULAS Empirical and molecular formulas are precise and informative but have disadvantages: – inconvenient for routine verbal communications – many compounds have the same empirical and molecular formulas but different arrangements of atoms, which results in different chemical and physical properties
Compounds & Molecules STRUCTURAL FORMULA BOND-LINE FORMULA
MOLECULAR FORMULAS • In one molecule of glycine there are • 2 C atoms • 5 H atoms • 1 N atom • 2 O atoms Empirical Formula _______________ Molecular Formula _______________ Structural Formula _______________
Representations of Molecular Structures 1. 2. 3. 4. 5. 6. • Different ways of representing the structure of a molecule • Molecular formula gives only the number of each kind of atom present. • Structural formula shows which atoms are present and how they are connected. • Ball and stick model shows the atoms as spheres and the bonds as sticks. • A perspective drawing, called a wedge-and-dashrepresentation, attempts to show the three-dimensional structure of the molecule. • The space-filling model shows the atoms in the molecule but not the bonds. • The condensed structural formula is the easiest and most common way to represent a molecule—it omits the lines representing bonds between atoms and simply lists the atoms bonded to a given atom next to it. Multiple groups attached to the same atom are shown in parentheses, followed by a subscript that indicates the number of such groups.
Chemical Compounds • Chemical bonds – two different kinds 1. Ionic — ionic compounds consist of positively and negatively charged ions held together by strong electrostatic forces. (Formula Mass) 2. Covalent — covalent compounds consist of molecules, which are groups of atoms in which one or more pairs of electrons are shared between bonded atoms. Atoms are held together by the electrostatic attraction between the positively charged nuclei of the bonded atoms and the negatively charged electrons they share. (Molecular Mass)
Ionic Chemical Compounds • Electrostatic attraction between oppositely charged particle species (positive and negative) results in a force that causes them to move toward each other. • Electrostatic repulsion between two species that have the same charge (either both positive or both negative) results in a force that causes them to repel each other • When the attractive electrostatic interactions between atoms are stronger than the repulsive interactions, atoms form chemical compounds and the attractive interactions between atoms are called chemical bonds.
Ionic Chemical Compounds • IONSare atoms or groups of atoms with a net positive or negative charge. • Taking away an electron from an atom gives a CATION with a positive charge • Adding an electron to an atom gives an ANION with a negative charge. • Ionic compounds contain both cations and anions in a ratio that results in no net electrical charge. CATION + ANION → COMPOUND • A neutral compound requires equal number of + and - charges. In general metals (Mg) lose electrons to become cations nonmetals (F) gain electrons to become anions Ionic compounds are held together by the attractive electrostatic interactions between cations and anions. Cations and anions are arranged in space to form an extended three-dimensional array that maximizes the number of attractive electrostatic interactions and minimizes the number of repulsive electrostatic interactions.
Physical Properties of Ionic Compounds • Ionic compounds – Usually form hard crystalline solids that melt at high temperatures and are very resistant to evaporation – Properties stem from the characteristic internal structure of an ionic solid, which is a three-dimensional array of alternating positive and negative ions held together by strong electrostatic attractions SiO PbS FeS
Binary Ionic Compounds • An ionic compound that contains only two elements, one present as a cation and one as an anion, is called a binary ionic compound. • For such compounds, the subscripts in the empirical formula can also be obtained using the absolute value of the charge on one ion as the subscript for the other ion and then reduce the subscripts to their simplest ratio to write the empirical formula.
Polyatomic Ions • Groups of atoms that bear a net electrical charge • Atoms that make up a polyatomic atom are held together by the same covalent bonds that hold atoms together in molecules • Many more kinds of polyatomic ions than monatomic ions and polyatomic anions are more numerous than polyatomic cations • Method used to predict empirical formula for ionic compounds that contain monatomic ions can be used for compounds containing polyatomic ions. Overall charge on the cations must balance the overall charge on the anions in the formula unit.
Table of Common Ions Common Positive Ions (Cations)
Table of Common Ions Common Negative Ions (Anions)
Hydrates • Ionic compounds that contain specific ratios of loosely bound water molecules, called waters of hydration. • Waters of hydration can be removed by heating. • Compounds that differ only in the numbers of waters of hydration can have very different properties.
Naming Polyatomic Ionic Compounds • Many compounds have more than one name: • 1. Common name — have historical origins • 2. Systematic name — write structure of the compound from its name and vice versa • Procedure for naming binary ioniccompounds, which contain only two elements, uses the following steps: • Place the ions in their proper order: cation and then anion • Name the cation • Metals that form only one kind of positive ion. These metals are in Groups 1–3, 12, and 13. The name of the cation of a metal that forms only one kind of positive ion is the same as the name of the metal • Metals that form more than one cation. These metals are transition metals, actinides, and the heaviest elements of Groups 13–15. Positive charge on the metal is indicated by a Roman numeral in parentheses following the name of the metal. • Name the anion • Monatomic anions — named by adding the suffix • –ide to the root of the name • of the parent element • Polyatomic anions • Have common names that must be learned • Polyatomic anions that contain a single metal • or nonmetal atom plus one or more oxygen • atoms are called oxoanions. Relationship • between names of oxoanions and number • of oxygen atoms present is:
Naming Polyatomic Ionic Compounds • Write the names of the compound as the name of the cation followed by the name of the anion. • – It is not necessary to indicate the number of cations or anions present per formula unit in the name of an ionic compound because information is implied by the charges on the ions • – When writing the formula for an ionic compound from its name the charge of the ions must considered.
Covalent Compounds • Physical Properties of Covalent compounds – Can be gases, liquids, or solids at room temperature and pressure, depending on the strength of the intermolecular interactions – Covalent molecular solids tend to form soft crystals that melt at low temperatures and evaporate easily – Consist of discrete molecules held together by comparatively weak intermolecular forces (the forces between molecules) even though the atoms within each molecule are held together by strong intramolecular covalent bonds (the forces within the molecule)
Covalent Compounds • Covalent compound are represented by a molecular formula, which gives the atomic symbol for each component element, in a prescribed order, accompanied by a subscript indicating the number of atoms of that element in the molecule C8H10N4O2 C4H10OBCl3 C3H6N6O6
Covalent Compounds • Inorganic compounds – Compounds that consist primarily of elements other than carbon and hydrogen – Include both covalent and ionic compounds – Formulas are written when the component elements are listed beginning with the one farthest to the left in the periodic table with those in the same group listed alphabetically • Organic compounds – Covalent compounds that contain predominantly carbon and hydrogen – Formulas of organic compounds written with carbon first, followed by hydrogen and then by other elements in alphabetical order
Inorganic Covalent Compounds • Some pure elements exist as covalent molecules • Hydrogen, nitrogen, oxygen, and the halogens occur as diatomic molecules and contain two atoms • A few pure elements, such as elemental phosphorus and sulfur, are polyatomic molecules and contain more than two atoms
Binary Inorganic Compounds • Binary covalent compounds — covalent compounds that contain only two elements • The procedure for naming them uses the following steps: 1. Place the elements in their proper order. • Element farthest to the left in the periodic table is named first. If both elements are in the same group, the element closer to the bottom of the column is named first. • Second element is named as if it were a monatomic anion in an ionic compound with the suffix –ideattachedto the root of the element name 2. Identify the number of each type of atom present. a. Prefixes derived from Greek stems are used to indicate the number of each type of atom in the formula unit. b. If the molecule contains more than one atom of both elements, then prefixes are used for both. c. With some names, the final a or o of the prefix is dropped to avoid awkward pronunciation. • Write the name of the compound. • Binary compounds of the elements with oxygen are named as “element oxide” with prefixes that indicate the number of atoms of each element per formula unit. b. Certain compounds are always called by their common names assigned long ago when names rather than formulas were used.