The “Chemistry and Life” box in Section 6.7 described the techniques called NMR and MRI. (a) Instruments for obtaining MRI data are typically labeled with a frequency, such as 600 MHz. Why do you suppose this label is relevant to the experiment? (b) What is the value of in Figure 6.27 that would correspond to the absorption of a photon of radiation with frequency 450 MHz? (c) In general, the stronger the magnetic field, the greater the information obtained from an NMR or MRI experiment. Why do you suppose this is the case?
FossilFuelsOverview Tuesday,February7,2017 2:27PM TheBig3 - Ourmainenergysourcestodaycomefrom3FossilFuels 1. Oil 2. NaturalGas 3. Coal Non-renewableResource :anaturalresourcethatcannotbere-madeorre-grownon atimescalecomparabletoitsconsumptionoruse RenewableResource :anaturalresourcethatisreplenishedoverashortperiodof time,quicklyenoughtoreplacewhatisconsumed Fossilfuelsarenon-renewableatcurrentrateofuse,becausetheyareproducedvery slowlybutweusethemrelativelyquickly Non-renewableResources:Reservesvs.TotalResources - Reserves:depositsknownandrecoverabletoday - Reservesareeconomicallyextractabletoday(foodonthetable) - Resourcesarethetotallyamountthatexists,someofwhichmaybecome economicallyextractableinthefuture(allthefoodinthesupermarket/being grownonfarmstoday) FossilfuelsareHydrocarbons(C -H) - Organiccompound - StorechemicalenergyintheC-Hbonds - Methane(CH )4 thesimplesthydrocarbon- hasthegreatestchemicalenergy (55kJ/gram) - Differenthydrocarbonsmakeupoilvs.gasvs.coal • NaturalGas=lighterhydrocarbons;methane(C 1)- pentane(C5);mostly methane • Gasoline=hexane(C)6- (C 12 • Lubricants=(C16andup MakingHydrocarbons Photosynthesis(CO +H O+light)synthesizesCarbohydratesCH O methane • Gasoline=hexane(C)6- (C 12 • Lubricants=(C16andup M