Chemistry for Life Sciences
Chemistry for Life Sciences CHEM 1210
Popular in Course
Rebeka Zemlak MD
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
Popular in Chemistry
This 38 page Class Notes was uploaded by Rebeka Zemlak MD on Wednesday October 21, 2015. The Class Notes belongs to CHEM 1210 at Tennessee Tech University taught by Staff in Fall. Since its upload, it has received 35 views. For similar materials see /class/225697/chem-1210-tennessee-tech-university in Chemistry at Tennessee Tech University.
Reviews for Chemistry for Life Sciences
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 10/21/15
Chapter 2 Atoms Are Atoms Real They are real Have observed computer enhanced images of atoms toms mage of atoms by SEM scanmng demon mxcroscope BMRLV s What we will learn Atomic theory 1 The law of conservation of mass 2 Dalton s atomic theory 3 The law of definite proportions 4 History of the periodic table Atoms Atoms are exceedingly small For example there are 1022 atoms in 1 penny Leucippus and Democritus postulated tiny particles of water that could not be subdivided further atomos ancient Greek Each type of atom has a distinct shape and size Atoms are the smallest characteristic particle of a given element Make up everything Different for each element 90 natural elements History of atomic theory 1The Greek idea by Leucippus Democritus vs Aristotle The atomistic view vs the continuous law 2The law of conservation of mass by Lavoisier Introduction of experimental chemistry to western society Matter is neither created nor destroyed during a chemical reaction I 3The law of definite proportions by Proust The law of definite proportions is strong evidence for the atomistic nature of matter If a matter is continuous any ratios by mass would be possible 4The Atomic theory of matter by John Dalton Generation of Atomic theory 5The periodic table JD established relative atomic masses to H atom Mendeleev arranged the element table Aristotle vs Atomists Everything was Water atoms are smooth continuous round balls Fire atoms are sharp 4 principles 4 elements 4 elements are quotwalled in by the forces of love and hatequot Atoms didn t exist Ancient Greeks Absolute love homogenous could not test either unlty model Hate separates them Continuous conflict ampmixing form all material HIS View prevalled for gt2000 years Antoine Lavoisier 17431794 Father of modern chemistry Accurately weighed starting materials and products of reactions The law of conservation of mass li39l 5 3 From Metropolitan Museum of Art Lavoisier Father of modern chemistry Accurately weighed starting materials and products of reactions The law of conservation of mass K 9357 grams of 643 grams of mercuric oxide mercury oxygen The mass of products equals the mass of the reactant No material is lost during a chemical reaction Law of Conservation of Mass Mass is neither created nor destroyed during chemical reactions Mass before Mass after One Cannot create material out of thin air You Make new materials by rearranging atoms Basis for chemical calculations 1g Zn powder with 02 g S were heated giving 06080 g zinc sulfide and 05920 g of unreacted Zn Does this obey the law of conservation of mass Methane gas consists of C and H When the gas was burned the only visible product was water vapor Was C atom destroyed C0 PhD 9 COZPb Carbon monoxide Lead oxide Carbon dioxide Lead Boyle Redefined elements If a substance cannot be broken down into simpler components the substance should be treated as an element Compounds are formed from two or more elements ex NaCl sodium chloride MgO magnesium oxide Matter Substances Mixtures Elements Substances have definite fixed constant compositions that do not vary from sample to sample Mixtures have composition that varies from sample to sample An element is one of the fundamental substances from which all things are constructed Cannot be broken into smaller things 114 elements known Not all found in nature Compounds Made of two or more elements chemically combined ex Water H20 ammonia NH3 Subscript indicates how much of each element is present Law of Definite Proportions Is the composition of Cookeville water the same as that of Boston or Tsunami water A compound has the same elements in a certain definite proportion and no other combinations Also implies compounds have constant properties Law of constant composition Established by Proust Is it possible to tell when reaction is complete or when too much starting material is present ume 1000 g of lead 155 g of sulfur 1155 g of lead sulfide gt quot9 1000 g of lead 300 g of sulfur 1155 g of lead sul de 145 g of sulfur leftovers amp r 539 1800 g of lead 155 g of sulfur 1155 g of lead sulfide 800 g of lead leftovers Conclusion The mass ration is fixed as 10155 for the reaction Law of Definite Proportions Conclusion chemicals are composed of one or more different components at a fixed ratio in mass not in a random ratio This applies to the same compound no matter where and when to produce a chemical naturally or artificially by this method or another End of Ancient Greek View Electrolysis of water separation of water into H amp O Proved water is not an element Shows there are H atoms and one atom H20 Molecular Formula Lines represent com 39 ti between atoms O H H St ructuml l39nrmul a Each element is represen different atoms m a ted by a an colored ball water molecule Ballunllstick model Space lling model Case studies 1 Jane measured 105 g of HgO into an open test tube and heated it The heat caused the H90 to decompose into Hg and 0 After reaction Jane finds that the mass of the contents of the tube to be 97 9 Which comment does describe this observation a The decomposition of H90 does not obey the law of conservation of mass b There are errors associated with the student s measurements c 08 g of 0 gas are lost from the tube d Heating destroys some mass Case studies ll 1 Stephanie heats 05585 g of Fe with 0355 g of 8 She reports That she obtains 08792 g of FeS and recovers 00433 g of unreacted S Show by calculation whether or not her results obey the law of conservation of mass 2 When 300 g of C is burned in 800 g of O 1100 g of CO2 is formed What mass of CO2 is produced when 3009 of C is burned in 5000 g of 0 What law does this illustrate Case studies lll 1 Heptane is always composed of 840 C and 160 H This illustrates the law of 2 When 1000 g of Pb and 156 g of S react 1156 g of PbS is produced Suppose 3000 g of Pb and 156 g of S are allowed to React Analysis of the reaction mixture would show that you have a 3458 g of PbS b 1156 g of PbS and 2000 g of S c No reaction d 1156 g of PbS and 2000 g of Pb Dalton s Atomic Theory 1 All matter is composed of extremely small particles called atoms Atoms are indivisible 2 All atoms of a given element are alike but atoms of one element differ from the atoms of any other element 3 Compounds are formed when different elements combine in fixed proportions These are typically written with smallest whole numbers 4 A chemical reaction involves only a rearrangement of atoms No atoms are created destroyed or broken apart in a chemical reaction modern view is slightly different Atomic Masses and Weight Relative atomic masses Based on hydrogen as 1 Many of Dalton s values were incorrect Modern chemistry use new values 9 Q3lt 2 Law of Definite Proportions by Dalton F is 19 times heavier than H 19 g of F combines with 1 g of H not 18 g or 20 9 How many grams of H will react with 38 g of F When 180 g of water is decomposed by electrolysis 160 g of O and 2 g of H are formed How much H is formed by the electrolysis of 630 g of water Confirmation of Law of Conservation of Mass Atoms are rearranged during the reaction No change in mass H2H2F2 gt HFHFH2 Relative mass of H 1 F 19 SB a CHEMICAL CONNECTIONS 2A Elements Necessary for Human Life To the best of our knowledge 20 of the 116 known elements are iecessary for human life The six most important of these carbon iydrogen nitrogen oxygen phosphorus and sulfur are the sub ects of organic chemistry and biochemistry Chapters 10 31t Carbon hydrogen nitrogen and oxygen are the quotbig fourquot in the iuman body Seven other elements are also quite important and our bodies use at least nine additional ones trace elements in very small quantities The table lists these 20 major elements and their functions in the human body Many of these elements are more fully discussed later in the book For the average daily requirements for these elements their sources in foods and symp toms of their deficiencies see Chapter 30 Table 2A Elements and Their Functions in the Human Body Element Function The Big Four Carbon lC Hydrogen H Nitrogen N Oxygen O The subject of Chapters 10715 organic chemistry and 20731 biochemistry The Next Seven Calcium Cal Strengthens bones and teeth aids in blood clotting Phosphorus P Present in phosphates olbone in nucleic acids DNA and RNA and involved in energy transfer Potassium K Helps regulate electrical balance ol body uids essential for nerve conduction Sulfur S Chlorine Cl An essential component of proteins Necessary for normal growth and development Sodium Na Helps regulate electrical balance in body uids Magnesium Mg Helps nerve and muscle action present in bones Element Function The Trace Elements Chromium Cr Increases eli39ectiveness oi39insulin Cobalt Co Copper Cu Part ofvitamin B12 Strengthens bones assists in enzyme activity Fluorine F Reduces the incidence oi39 dental cavities Iodine I An essential part of thyroid harm on es Iron Fe An essential part of some proteins such as hemoglobin myoglobin cytochromes and FeS proteins Manganese Mn Present in bonefonnjng enzymes aids in rat and carbohydrate metabolism Molybdenum Mo Helps regulate electrical balance in body uids Zinc lZn Necessary for the action ol39 certain enzymes Table 2B The Relative Abundance of Elements in the Human Body and in the Earth39s Crust Including the Atmosphere and Oceans Percentage in Human Body Percentage in I By Number By Earth39s Crust Element of Atoms Mass by Mass H 630 100 09 O 254 648 493 C 94 180 008 N 14 31 003 Ca 031 18 34 P 022 14 012 K 006 04 24 s 005 03 006 Cl 003 02 02 Na 003 01 27 Mg 001 004 19 SI 7 258 A1 i 76 Fe 7 47 1 Others 001 i i r 39 N 395 gble 211 Properties and Location within Atoms of Protons Neutrons and Electrons Mass amu Subatomic Mass Mass Rounded to One Location in Particle Charge 9 amu Significant Figure an Atom l Proton 1 16726 X 10 34 10073 1 In the nucleus b Electron 1 91094 X 1039 54859 X 10 00005 Outside the nucleus Neutron 0 16749 X 10quotquot 1 In the nucleus Proton A subatomic particle with a charge of 1 and a mass of approximately 1 amu it is found in a nucleus Atomic mass unit amu A unit of the scale of relative masses of atoms 1 amu 16605 x 10quot g By de nition 1 amu is 112 the mass of a carbon atom containing 6 protons and 6 neutrons Electron A subatomic particle with a charge of 1 and a mass ofapproximately 00005 amu It is found in the space surrounding a nucleus Neutron A subatomic particle with a mass of approximately 1 amu and a charge of zero it is found in the nucleus Two protons repel each other gt4i Two electrons A pmth and an repel each other electron attract each other Nucleus Space protons and occupied by neutrons electr ns Proton Neutron Figure 26 A Lypical atom Protons and neutrons are found in the nucleus and electrons are found as a cloud outside the nucleusl Notice how small the nucleus is compared to the size of an atom Mendeleev s Periodic Table Arranged in order of increasing atomic mass and by chemical property Some elements don t fit where their atomic mass suggests TABLE 22 Periodic Table 0 Mendeleev39 Gruppe 1 Gruppe 2 Gruppe 3 Gruppe 4 Gruppe 5 Gruppe 6 Gruppe 7 Gruppe 8 RH 113 RHZ Reihen R20 R0 11203 R02 R205 R03 R207 110 1 1 H 1 Z Li7 3994 1311 C212 N14 0216 F219 3 Na 23 Mg 24 AI 273 Si 28 P 31 S 32 C1 355 4 K39 Ca40 44 Ti48 V51 Cr52 Mn55 Fe56Co59 Ni 2 59 Cu 63 5 Cu63 Zn65 68 72 As75 8678 Br80 6 Rb 85 Sr 87 Yt 88 Zr 90 Nb 94 M0 96 100 Ru 104 Rh 104 Pd 106 Ag 108 7 Ag 108 Cd 112 In 113 Sn 118 Sb 122 Te 125 J 127 8 C5 133 Ba 137 Di 138 Ce 140 9 10 Er 178 La 180 Ta 182 W 184 05 1951r 197 Pt 1981 Au 199 11 Au 199 Hg 200 Ti 204 Pb 207 Bi 208 12 Th231 U240 quot Spaces ar Missing Elements Left gaps in order to place elements with similar properties in correct locations in the table Predicted properties of missing elements for example germanium Property Predicted Observed Atomic mass 72 726 Density 55 547 gcm3 Color Dirty gray Grayish white Modern Periodic Table with classification of elements L i H Metala 1 MetaJluida Ij Nonmemls HE 2A 3A SA SA Be E c H a F Ne NE ME 312 413 513 SB TB SE SE SE 13 213 Al 5 P 5 m 51 KIDaEuTiV ImMuFE uHi uZnGa e EEeEr r Rh a if z Nh Mn Tie Ru 1231 Ed Ag Dd In E Sb Tie I Re Ba Ba La HF 3911 W RE 05 Ir Pl 11 Hg T1 Fb Bi Pm At Rn Fr Ea A t Db 3g Eh Ha Mt a at at at at at Not yer named Data from Periodic Table 26 lt atomic number Z Fe 4 Chemical symbol 55847 lt atomic mass weighted average E Atomic Weight The atomic weight of an element given in the Periodic Table is a weighted average of the masses in amul of its isotopes found on Earth As an exam ple of the calculation of atomic weight let us examine chlorine As we hate just seen two isotopes of chlorine exist in nature chlorine35 and chlorine 3 The mass of a chlorine35 atom is 3497 amu and the mass of a chlorine 37 atom is 369 amu Note that the atomic weight of each chlorine isotope its mass in amu39II is very close to its atomic number the number of protons and neutrons in its nucleus IThis statement holds true for the isotopes of chlorine and those of all elements because protons and neutrons have a mass of approximately I39hut not exactly 1 amu The atomic Weight of chlorine is a weighted average of the masses of39che two n tLil39 ljquot occurring chlorine 180L0p1351 14 Chlorine35 Chlorine 37 Cl l 3393 354527 Ir F P l quoti quot u I quot 39v 5 a 39 3433 I I n 11le l IUD V 34 9 111111 1m 26 j 2 J4 amu 35 45 3911 nu Atomic weight in the Periodic Table is given Atomic welght The weighted average of the masses of the naturally occurring isotopes of an element The units of atomic weigh are atomic mam units Eaton r to39foLu39 decimal places Electron Configurations and Periodic Table Each column is a group or family Elements in each group have similar properties Common groups alkali metals alkaline earth metals halogens and noble gases Each row is a period Properties vary across each Outer Electron Configurations Valence electrons electrons in outermost shells Determines chemistry Elements in the same group have the same number of valence electrons EX Group 1 Alkali metals 1 valence e Group 2 Alkaline earth metals 2 valence e Group 7 Halogens 7 valence electrons Group 8 Noble gas 8 valence e except He Periodic Table Blocks Correspond to different subshells s and p block Main group elements d block transition metals fblock inner transition metals p w 1 H a H l U l B l l ll a 7 7 l s A g a r39 39 l 39l quot 39 1 I r i 1 l l A z z gt J I l A J l
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'