Notes for Lab Exam

4 Pages
Unlock Document

University of Toronto Scarborough
Effiette Sauer

Lab 1 Distillation Distillation: • Process of boiling liquid to vapour then condensing back to liquid (=distillate) Bulb is under side arm of distillate head Simple distillation • for pure compounds, distilling miscible or immiscible liquids Fractional distillation • for miscible liquids, azeotropes Azeotrope: • solution that does not behave as an ideal solution and does not obey Raoult's law, behaves like a pure liquid, distills at constant temperature and composition Raoult's Law: • Equilibrium between liquid and vapour pressure of pure substance --> not related to volume • Pa=Xa*Pa Boiling point: • Temperature at which vapour pressure is equal to atmospheric pressure Theoretical Plate: • region along the fractional column where liquid and vapour phase are in equilibrium • #Theoretical Plate = Rate of column efficiency Separating liquids must have a difference of 20 deg C Distill at 1-1.5 ml/min Prelab: • Distill slowly to keep equilibrium --> avoid superheating + poor separation • Thermometer position --> to get bathed in true bp temperature with condensed droplet • ≤ 2/3: prevent bumping, slower distillation by little SA • ≥ 1/3: prevent dry flask, crack or explode (dried ether) Remember: Grease joints, add new boiling chips, put foil on fractionating column, bulb position, clamp RB flask, clamp condenser, graduated cylinder position Lab 2 Extraction Trimyristine extracted from Myristica fragrans from myristic acid (III) and glycerol Reflux: • conservation of liquid volume in the cycle of evaporating liquid to vapour and condensing again to speed up reaction (thru heat) Gravity filtration: • Use glass pipet because there is no loss of yield, unlike filter paper Used acetone because water has low bp and low mp (evaporate) Prelab: • Use diethyl ether vs acetone because S in ether, I in acetone --> force out Trymyristine crystals • Fat vs oil --> liquid or solid at room temp. Trimyristine is saturated (no double bonds) • Impurities in a mixture act as impurities on each other --> no crystals Lab 3 Solubility • Low C # less than 5 • Intermediate C # 6-9 • High C # over 9 H20 - I for high C organic Ether - S all organic *except polar 5% HCl - S organic base 5% NaOH - S organic acid 5% NaHCO3 - S COOH, I Phenol (=weak base) H2SO4 - High C #, double bonds, O Identifying layer by cheapest solvent drop Prelab • Solubility of organic base higher in water because acid base reaction • Wet filter with cold water because low solubility using vacuum filtration Purpose of vacuum filtration is to decrease Temp --> decrease solubility and extract product • • If exp MP differs from lit. MP --> impurities Lab 4 Recrystallization Recrystallization: • Purifying impure solid chemicals • Pure solids melt up to 20 deg C above room temp -- hard to crystalliz
More Less

Related notes for CHMB41H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.