organic analysis

add sodium solid alcohol + sodium -> sodium ethoxide and hydrogen test for hydrogen gas with squeaky pop test. put burning splint near mouth of test tube. oxygen in air and hydrogen will react to form a pop dispose of excess sodium with excess alcohol

add fehlings a and fehlings b in equal amounts. mix. and anti bumping granules add wool on top to minimise fumes warm gently in hot water bath allow to stand fehlings solution oxidises aldehydes, forming c acid which dissociates yo form a carboxylate ion

prepare tollens by adding silver nitrate and sodium hydroxide AgNO3+ NaOH -> AgOH + NaHO3 then 2AgOH -> Ag2O + H2O then add aw ammonia Ag2O + H2O + 4NH3 -> 2Ag(NH3)2.+ + 2OH- tollens reagent will oxidise aldehyde into c acid. as it does this silver ions in tollens reagent are reduced to silver atoms forming precipitate of silver on the inside of the test tube

add bromine water which is brown and shake vigorously. C=C will be attacked by Br2 electrophiles by electrophilic addition forming bromo alkanes brown to colourless

add a carbonate eg NaHCO3. acid plus carbonate goes to salt plus carbon dioxide plus water need a set up of two tubes to collect gas formed. delivery tube between them with bungs in both. reaction in one, gas produced will go into other. the other tube should have Ca(OH)2, limewater, in it. limewater goes cloudy when CO2 because forms CaCO3, precipitate

add NaOH which will act as a nucleophile and form alcohols and halide ions then becomes test for halide ions: add nitric acid to neutralise other ions that could form positive results add silver nitrate. will dissociate, silver ions react with halide ions to form solid silver halides. Cl, Br, I; white, cream, yellow if need more: add dilute ammonia, will redissolve AgCl. add conc ammonia, will redissolve AgBr

Mass spectrometry is an analytical technique used to determine the mass-to-charge ratio (m/z) of ions. It helps in identifying and quantifying molecules based on their mass and structure. Determines the molecular mass of an unknown substance. find the molecular mass of a compound by determining it’s mass to charge ratio. sample is usually 1+ charge because of electrospray or electron impact. so yeah used to find abundance of isotopes and consequently the average molecular mass (if 2+ then the m/z will be half actual mass // if electrospray then mass is m/z - 1 because that 1 represents the H ion added)

an analytical technique which allows for more precise measurements of the ions mass In MS the sample is vaporized, ionized, and accelerated towards a negatively charged plate where a current is induced portion or to an ions abundance in high resolution must spectrometry the mass analyzer is able to separate ions with very similar m/z ratio, measuring it to several decimal places therefore providing exact masses how? the computer calculating mass (w the saem eqs we do) is able to detect time taken and other vairables potentially, to a much higher precision

measure Mr to many dp compare mass to mass of constituent elements to find molecular formula give a more sensitive form of mass spec

an analytical technique using infrared radiation to determine the function of groups in an organic compound

when infrared radiation is passed through a compound it will absorb the light at the frequencies at which its bonds vibrate. bonds in a molecule absorb infrared at characteristic wave numbers. different bonds absorb the radiation in different amounts. these varying amounts of absorbance / transmittance or measured + recorded on a spectrum allowing certain bonds and therefore functional groups to be identified

smooth wide dip in wavenumber range

rougher wide dip (than alcohols - this is how you detrmine if alcohol or acid oh. also, presence of c=o) this is due to very strong H bonding. the stronger the H bonding the broader the peak. the dip can go beyond 3000 but if it begins before and has a rougher wide dip, acid. Not oh alcohol because that’s only above 3000 and smooth

broad

narrow sharp curve

narrow sharp curve this range is quite unique to c=o therefore its often known as the carbonyl peak range or smth like that. easy to spot and assign

above 1500 wavenumbers the spectrum is unique to a compound therefore it can be used to check the purity of a sample,, or identify a compound by comparing unknown chemical data of the fingerprint region to known data: if there is an exact match is the same chemical

1/ wavelength of radiation used to measure the wavelength / frequency of absorption

can find structure of molecule other analytical techniques cana be used like NMR or chromatography

temperature being high enough to have liquid water because bonds in carbon dioxide, methane, and water vapor absorb infrared radiation this is crucial because biochemistry is water based. the temp being warm enough because GHG absrob IR radiation that has been radiated from earths surface allows for a stble warm climate that provides conditions for chemical reactions and complex molecules due to the addition of molecules in the atmosphere such as co2 and cfc’s due to human activity, this heating effect is exacerbated leading to global warming. too many of these gases –> too much IR absorbed –> too much trapped heat

enhanced understanding of organic molecules that structure and the way they react analytical techniques can be as simple as test tube reactions or as complex as mass spec and ir spectroscopy

molecules eg CO2, H20 AND CH4 absorb infrared radiation because their bonds vibrate when exposed to IR. bonds absorb radiation at frequencies that make their bonds vibrate. each type of bond absorbs specific infrared frequencies