The chief aim of this lab is to place the given unknown organic compounds with assorted methods. Designation of an unknown compound is of import to execute through the procedure of runing point ( M.P ) , boiling point ( B.P ) and Infrared spectrometry ( I.R ) . Index of Hydrogen lack ( IHD ) and elemental analysis makes an experiment more efficient in finding of unknown compound. The colour, olfactory property, runing point and boiling point determines the physical province and belongingss of a compound. It besides determines its volatility in regard to temperature.
The functional group of a compound can be determined on a footing of a spectra formed by a NICOLET iS5 FT infrared spectrometer. The IR sample of a liquid is obtained on a pure liquid called a orderly sample whereas solid sample was obtained with the aid of an Attenuated entire coefficient of reflection IR spectra. The index of H lack determines the impregnation of a compound ( dual bonds, ternary bonds or rings ) .
Elemental analysis helps in finding the molecular expression of a compound. The boiling point of an unknown liquid sample was determined with a mini graduated table technique. It consists of a warming mantle, a long narrow Pyrex text tubing and heating rock. The thermometer is placed 2 centimeters above the degree of liquid to acquire an accurate readings. Melting point of a sample was determined by electric runing point setup.
The runing point of the crystalline solid is determined by heating the jammed capillary tubing until the solid thaws. The accurate step of runing point is obtained by heating at the rate of 1-2oC/min to guarantee the heat is transferred to the sample rate as the temperature additions and the quicksilver in the thermometer and the sample in capillary tubing are in thermic equilibrium. The boiling point and runing point of unknown compounds helps to corroborate the conjectural construction from unknown to cognize compound.
Experimental Procedure
Two unknown organic compound was given one solid and other liquid. A runing point of a solid was determined with the aid of an electric thaw
setup. A sample of crystal solid was taken in a bulb of capillary and inserted inside the thaw setup. The temperature difference of 1-20C/min was maintained. Two trails of initial and concluding temperature were taken. The initial temperature was noted when the first bantam bead of liquid appears and concluding temperature was noted when all crystal was wholly melted.
Boiling point was performed with the aid of mini graduated table technique. 0.5-1.0 milliliter of liquid was taken in a clean trial tubing, clamped and held on top of a warming mantle. A thermometer was placed merely 2 centimeters above the liquid with another clinch. Two trails of reading were noted. Initial temperature was taken when the first bubble came out whereas concluding temperature was taken when there was a vigorous motion.
Both samples of solid and liquid were so scanned to a NICOLET iS5 FTIR operating spectrometer. The surface was carefully cleaned with the beads of propanone to a Q-tip and gently wiped the ATR crystal and force per unit area tip to clean. The spectrum of background was collected foremost to guarantee the machine was working mulct and so the sample spectra was collected and printed. Data Acquisition
The unknown solid compound obtained from the elemental analysis and composing was C7H6O2. Harmonizing to the computation of IHD of 5 ( i.e. 4 dual bonds and 1 ring ) and the functional groups obtained from the spectra was similar to the hypothesis construction, benzoic acid. The experimental value of runing point of benzoic acid was 116.7 and was about close to the value found from mention book which was 122.41. The mistake might be the drosss from container.
The liquid compound obtained from similar procedures had an empirical value C5H10O. The IHD for the compound came 1 which might be 1ring or dual bond. Since, the sample had a strong odor, and the spectrum was similar to the hypothesis construction, 2- Pentanone. Experimentally, the boiling point of Pentanone or propanone was 950C. But from
mention it was 1010C. The mistake in boiling point of experiment might be due to the drosss found in trial tubing.
