Lab 12: Reduction of an Aldehyde to a Primary Alcohol by Use of NaBH4

Lab 12: Reduction of an Aldehyde to a Primary Alcohol by Use of NaBH4Purpose(i)To select an separate solvent system. (ii)To synthesize heady from aldehyde by NaBH4 reduction. (iii)To identify the aldehyde isomer found on the melting surf point of the inebriant produced. Procedure(Please adjoin to the comminuted instructions on cognizance laboratory 12 handout)Physical bar TableType of substanceMolecular FormulaMolecular Weight (g/mol)Density(g/cm3)Melting Point(oC)Boiling Point(oC)HazardO-vanillinC8H8O3152.15-42.5265-266Harmful andIrritantFor all 3vanillinC8H8O3152.151.05680-81285isovanillinC8H8O3152.15-113-115179Vanillyl intoxicantic beverage*C8H10O3154.17-113-115--Sodium hydrated oxide**NaOH39.992.13181390CorrosiveHydrochloric acidHCl36.461.18-26110CorrosiveSodium borohydrideNaBH437.831.074505400IrritantCorrosive*Vanillyl alcoholic beverage is disintegrable in cold extreme solvents much(prenominal) as ether/alcohol and hot water, but insoluble in cold water. ** upkeep: Should not touch NaBH4 like a shot with skin. Result and CalculationMass of aldehyde #1 (starting material) = 0.3999 gMass of alcohol #1 (product) = 0.1573 g alcoholTheoretical raise = 0.3999 g vanillin x (154.17 g alcohol/152.15 g vanillin) = 0.4052gPercentage composition = (actual yield/theoretical yield) x 100%= 0.1573 g alcohol/ 0.4052 g alcohol = 38.8% outcome system chosen = ethyl acetate and hexane in 9:1 ratioMelting point purge of alcohol #1 = 108oC -109oCObservationWhen the NaOH was added to the aldehyde #1, the dissolving agent turned yellowish green. It took 10 minutes for the white hearty NaBH4 to completely dissolve in the aldehyde solution. When the HCl was added, the solution fizzed and bubbles came off. White settle formed.

After the vacuum filtration, shiny white crystalline unscathed was found. DiscussionFrom the melting point elaborate of the alcohol 108oC -109oC, it could be unyielding that the aldehyde isomer used should be vanillin, since vanillin produces vanillyl alcohol that has the melting point domain of 113 oC -115oC which is quite close to the experimental melting point range. The smooth depression could be collectible to the impurities present in the solid such as water. In this experiment, the vanillin is converted into vanillyl alcohol by formation of alkoxide ion, followed by protonation. The elaborate mechanism was shown below: change state layer... If you want to get a full essay, order it on our website: Orderessay

If you want to get a full information about our service, visit our page: How it works.