General Chemistry Week Three Notes
General Chemistry Week Three Notes CHEM103090
Popular in General Chemistry
Popular in Health and Human Services
This 5 page Class Notes was uploaded by Nina Drachman on Saturday September 19, 2015. The Class Notes belongs to CHEM103090 at University of Delaware taught by Graves PhD,Kimberly Susan in Fall 2015. Since its upload, it has received 70 views. For similar materials see General Chemistry in Health and Human Services at University of Delaware.
Reviews for General Chemistry Week Three Notes
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: 09/19/15
Chemistry Lecture Sep 15 Chapter 3 The Mole and Compound Formulas Using Compound Nomenclature A compound s name tells us things about it o What type of bonds 0 Which elements and how many atoms Ex sulfur tri oride l molecular compound with covalent bonds connecting one sulfur to three uorines pre x only on molecular covalent compounds The Mole Concept Standard unit for expressing macroscopic quantities atoms or molecules of elements or compounds 6022 x 10quot23 atoms in one mole Avogadro s number Mole as a Conversion Factor Number of particles x 1 mole6022 x 10quot23 particles number of moles Number of moles x 6022 x 10quot23 number of particles Molar Mass The mass in grams equal to the mass of the individual atom or molecule in amu The mass in grams of one mole of the substance atom molecule or formula unit 0 1 atom of He 4003 amu o 1 mole of He 6022 x 10quot23 4003 g The molar mass M of He is 4003 gmol What is the molar mass of hydrogen gas H2 202 gmol 101 x 2 from the second hydrogen 202 Molar massmass of one mole of something same as we see on periodic table units are gmol Conversions Moles to Mass Grams x 1 molg moles Moles x g1 mol grams Percent Composition Mass percent of each element in a compound can be measured by decomposing compound and measuring mass of each element a different from relative numbers of elements because each element has different mass Ex sulfur trioxide l 503 0 Total sample 801 g 503 0 Mass of sulfur measured 321 g 0 Percent of sulfur 321 g S801 g 503 x 100 401 0 Mass of oxygen measured 480 g 0 Percent of oxygen 480 g O801 g 503 x 100 599 Is it a Vitamin Vitamin C 0 4092 C 458 H and 5450 0 Major component of Vitamin E 0 8093 C 1163 H and 744 O Recovered powders percent composition measured 0 5995 C 448 H and 3552 0 o Not ghU Connecting Mass to Formula Empirical formula simplest wholenumber molar ratio of elements in a compound Find mass of each element in a sampleassume 1009 of substance Find moles of each element in a sampleljconvert masses using molar mass of element Compute mole ratiosdivide by smallest number of moles to compare elements Convert to smallestwhole number ratios by multiplying by common factor Chemistry Lecture Sep 17 Focus Question Reducing Carbon Dioxide Current fuel usage produces a large amount of carbon dioxide Which fuels might reduce the carbon dioxide amounts Identifying a Compound From Composition Recovered powder s mass percent composition measured 5995 C 448 H and 3552 0 C9H804 How do we Determine Percent Composition Priestly Aug 1774 0 Mercury calx o Discovered oxygen Lavoisier Oct 1774 o How much mass it started with and then how much the two masses are 92613 Hg10000g Compd 92613 7387 g 010000g Cmpd 7387 Connecting Mass to Formula Empirical formula simplest wholenumber molar ratio of elements in a compound Another Way to Break Down Materials Burn them Combustion Reactions Often explosive reaction of a compound with oxygen Fuel oxygen l gases heat Ex of common fuel methane gas CH4 g 02 g C02 g H20 g Natural Gas as Fuel Natural gas a mixture of light hydrocarbons composed mostly of methane The US has vast reserves of natural gas released from fracking a land lls but because it is a gas it can t easily be transported 140 billion cubic meters of natural gas is estimated to be ared each year Hydrates A hydrate is a compound containing water molecules combined in a de nite ratio as an integral part of the crystal Naming Hydrates Formula for hydrates includes a dot followed by the formula numbers of quotwaters of hydrationquot 0 Ex CaCl2 x 6 H20 To name a hydrate name as normal then add quotpre x hydratequot to note the number of water molecules 0 CaCl2 x 6 H20 calcium chloride hexahydrate o CuSO4 x 5 H20 copper ll sulfate pentahydrate
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'