Nuclear Magnetic Resonance. It is a technique that exploit the magnetic properties of certain atomic nuclei not on atom. Absorption in the low-energy radio-frequency part of the spectrum causes excitation of nuclear spin states in the nuclei of some atoms. Some nuclei like H1, C13, and P31 have nuclear spin. It determine the chemical and physical and chemical properties of atom or molecules in which they are contained. It relies on the phenomena of nuclear magnetic resonance and give detail information about thestructure , dynamic , reaction states and chemical environment of molecules.It also use to confrm the identity of substance. Diferent functional group are obiously distinguishable 1. The number of peaks. The number of peaks is directly related to symmetry. If a compound hasthree signifcantly diferent types of hydrogens, it should have three diferent NMR absorptions.2. The area under each absorption (the integral). The relative areas (or integrals) of the various absorptions in an NMR spectrum equals the relative number of hydrogens absorbing. .3 The position of the peak or the chemical shift . This tells you about the electronic environment (the electronic environment directly relates to the magnetic environment) of the absorbing hydrogens. It will tell you if there are pi bonds or electronegative atoms nearby, etc(1)Internal Energy:- The sum of kinetic energy and potential energy is termed as internal energy of the system. It is denoted E or E = K.E + P.E. Kinetic energy is due to motion while potential energy is due to intr and intermolecularforces of attraction Internal energy of a system cannot be measured, while change in internal energy canbe measured. It is denoted by E. E = qv Internal energy is a state function depends on the initial and fnal state of the system. When change in internal energy occurs, there are three possibility depends on theamount of energy released or absorbed.(i) Only temperature change.kinetic energy of the molecules change(ii) Physical change occurs. Like melting or boiling(iii) Chemical change occurs. When sufcient energy supplied to break the bonds.State and State Function: - The condition which describes the system is called state of the system. The state is described by P, V, T and number of moles. The state before change is called initial state. The description of a system after change is called fnal state. The property of the system, which depends on the state of the system and not on the path through which the system bring about a change, is called state function. The value of this property depends only on the state of system and is independent on the way of change.It is also called state property or state variable.Pressure, volume and temperature are state function.They are represented by capital letter like P,V and THeat and work are not state functions.Superacids and superbases. The term superacid was originally coined by James Bryant Conant in 1927 to describe acids that were stronger than conventional mineral acids.[1] George A. Olah prepared the so-called magic acid, so-named for its ability to attack hydrocarbons, by mixing antimony pentafuoride (SbF5) and fuorosulfonic acid (FSO3H). The name was coined after a candle was placed in a sample of magic acid. The candle dissolved, showing the ability of the acid to protonate hydrocarbons, which under aqueous acidic conditions cannot be protonated.At 140 C , FSO3HSbF5 converts methane into the tertiary-butyl carbocation, a reaction that begins with the protonation of methaneFluoroantimonic acid, HSbF6, can produce solutions with H0 down to 28.[3] Fluoroantimonic acid is made by combining HF and SbF5. In this system, HF releases its proton (H+) concomitantwith the binding of F by antimony pentafuoride, which (as described below) is a Lewis acid. Theresulting anion is both a weak nucleophile and an extraordinarily weak base.Superacids are useful in reactions such as the isomerization of alkanes. Industrially, anhydrous acid-exchanged zeolites, which are superacid catalysts, are used on a massive scale to isomerize hydrocarbons in the processing of crude oil to gasoline. Superbases such as lithium diethylamide (LiNEt2), alkyllithium compounds (RLi), and Grignard reagents (RMgX) useful in a broad range of organic reactions. LiNEt2 deprotonates C-H bonds to generate reactive carbanions. RLi and RMgX are powerful nucleophiles.The use of superbases in nonaqueous media allows us to rank the acidities (and measure the pKa's) of diferent classes of molecules. This ranking is particularly important in understanding the reactions of organic molecules. Note that the order of acidities for hydrocarbons is alkynes >>alkenes, aromatics >> alkanes. This ordering has to do with the hybridization of the carbon atom that forms the carbanion. The negatively charged lone pair of the carbanion is stabilized in orbitals that have high s character (e.g., sp vs. sp2 or sp3). This is because s orbitals have fnite probability density at the nucleus and "feel" the positive nuclear charge (thereby stabilizing the extra negative charge on carbon) more than p orbitals. Resonance efects also stabilize carbanions. Thus, cyclopentadiene is more acidic than even an alkyne because the negative charge is delocalized over the entire (aromatic) C5H5- ring when the C5H6 is deprotonated.