Orgo Lab Pre Labs
Pre-Lab 9: What happens to form the brown spots on a TLC plate when you place the developed TLC plate in an iodine chamber?
In order to form the brown spots on the TLC plate, the iodine vapors must be absorbed by the organic compounds on the plate.
Pre-Lab 9: Why can you not selectively epoxidize an alkene with MCPBA in the presence of a ketone
Ketone will be converted to an ester
Pre-lab 6: What is the Molecular Weight, Melting point, Solubility, Boiling Point, density, grams used, and moles used of the following reagents? Table of Reactants: 1) 1-butanol 2) acetic acid What is the Molecular Weight, Melting point, Solubility, Boiling Point, density, and theoretical yield of the following reagent? Table of Products: 1) N-butyl Acetate
Reactants: 1) 74.12 g/mol, -90C, in water: 73 g/L, 118C, 0.810g/mL, 0.74, 0.01 2) 60.05 g/mol, 17C, Miscible w water, 117.9 C, 1.05g/mL, 0.60, 0.01 Products: 1) 116.16g/mol, -77C, in water: 0.68g/ 100 mL, 126.5C, 0.882, 1.16g
Pre-Lab 2: What is the Molecular Weight, Melting point, and solubility of the following reagents? Possible Solids Being recrystallized: 1) Acetanilide 2) Salicylic Acid 3) Ethanol
1) 135.17 g/mol, 113-115C, slightly soluble 2) 138.13 g/mol, 158-160C, Soluble in:water, acetone, chloroform, diethyl ether, ethanol, methanol, propanol 3) 46.07 g/mol, 113-115C, In water: 1000g/L and also soluble in:ethyl ether, acetone, chloroform, benzene, and many organic compounds
Pre-Lab 1: What is the Molecular Weight, Melting point, and solubility of the following reagents? 1) Cinnamic Acid 2) Urea 3) Benzoic Acid 4) Acetanilide 5) Benzophenone 6)4-Nitrotoluene 7) Salicylic Acid 8) M-Toluic Acid 9) 1,2 Benzanthracene 10) R,S- Mandelic Acid
1) 148.16 g/mol, 131-133C, in water: 0.4g/L 2) 60.06 g/mol, 131-135C, Soluble in water 3) 122.12 g/mol, 121-123C, In water: 2.9g/L 4) 135.17g/mol, 113-115C, slightly soluble 5) 182.07 g/mol, 47-49C, not soluble in water but soluble in ethanol 6) 137.14 g/mol, 51-54C, In water: 0.35g/L and also soluble in ethanol, ether, acetone, benzene, carbon tetrachloride, chloroform, pyridine, toluene, and carbon disulfide 7) 138.12 g/mol, 158-160C, soluble in:water, acetone, chloroform, diethyl ether, ethanol, methanol, propanol 8) 136.15 g/mol, 108-112C, moderately soluble 9) 228.39 g/mol, 158-161C, INSOLUBLE in water and soluble in most organic compound 10) 152.15 g/mol, 118-122C, In water: 150g/L
Pre-Lab 5: What is the Molecular Weight, Melting point, Solubility, Boiling Point, and density of the following reagents? 1) 4-tertbutylphenol 2) Benzoic Acid 3) Ethanol 4) Biphenyl 5) t-butyl-methyl-ether 6) water
1) 150.22g/mol, 101C, Water: low (0.58mg/mL at 25∘C) Ether: Moderately soluble Ethanol: Soluble, 237C, 0.908g/mL 2) 122.12 g/mol, 122.4C, Water: 3.44 g/L at 25∘C Also Soluble in ether and ethanol, 249.2C, 1.2659g/mL 3) 46.07g/mol, 113-115C, in water: 100g/L and also soluble in: ethyl ether, acetone, benzene, and chloroform Soluble in many organic solvents, 78.37C, 0.789g/mL 4) 154.21 g/mol, 71C, Water: very low (7.48mg/L at 25 ̊C) Also soluble in Ether and Ethanol, 255C, 1.130 g/mL 5)88.15g/mol, -109C, in water: 4.8g/100mL at 25 ̊C and also soluble in ethyl ether and ethanol, 55.1C, 0.740 g/mL 6) 18.02g/mol, 0C, Water: yes, 100C, 1.0g/mL
Pre-Lab 4: What is the Molecular Weight, Melting point, Solubility, Boiling Point, and density of the following reagents? 1) Acetaminophen 2) Aspirin 3) Caffeine 4) Ethanol 5) Methylene Chloride 6) Ethyl Acetate
1) 151.16 g/mol, 168-170C, in water: 10.97 g/kg and Also soluble in ethanol, 420 C, 1.26g/mL 2) 180.16 g/mol, 135-138C, in water: 3.3 g/L and Also soluble in ethanol, 140C, 1.40g/mL 3) 194.19 g/mol, 235-237C, in water: 2.17 g/100mL and Also soluble in ethanol, 178C, 1.23g/mL 4) 46.07g/mol, 113-115C, in water: 100g/L and also soluble in: ethyl ether, acetone, benzene, and chloroform Soluble in many organic solvents, 78.37C, 0.789g/mL 5) 84.93 g/mol, -95 to -97C, in water: 13g/L at 25C and 50 mg/mL at 70F, 39.6-40C, 1.33g/mL 6) 88.11 g/mol, -84C, in water: 80g/L, 77C, 0.90 g/mL
Pre-Lab 7: What is the Molecular Weight, Melting point, Solubility, Boiling Point, density, grams used, and moles used of the following reagents? Table of Reactants: 1) Acetone 2) Benzaldehyde 3) Ethanol 4) Sodium Hydroxide What is the Molecular Weight, Melting point, Solubility, Boiling Point, and theoretical yield of the following reagents Table of Products: 1) 4-hydroxy-4-methyl-2-pentanone 2) Benzalacetone 3) Dibenzalacetone
1) 58.08 g/mol, -95C, Water: miscible, 56C, 0.79g/mL, 0.058g, 0.001 2) 106.12 g/mol, -26C, in Water: 6.95 g/L, 178.1C, 1.044 g/mL, 0.212g, 0.002 3) 46.07g/mol, 113-115C, in water: miscible, 78.37C, 0.789g/mL, 1.206g, 0.026 4) 39.99 g/mol, 318C, 1388C, in water: 1000g/L, 1388C, 1.515 g/mL, 0.240 g, 0.006 Table of Products: 1) 116.16 g/mol, -47C, in water: moderately soluble, 166C 2) 146.19 g/mol, 39C, Soluble in ethanol and acetone, 235C 3) 234.3, 110C, in water: insoluble and soluble in ethanol, 130C, 0.234g
Pre-Lab 3: What is the Molecular Weight, Boiling point, and density of the following reagents? 1) Cyclohexane 2) Toluene
1) 84.16 g/mol, 80.7C, 0.779g/mL 2) 92.14 g/mol, 110.6C, 0.865 g/mL
Pre Lab 1: Where do the following items need to be disposed after carrying out the melting point experiment? 1) Melting Point Capillary after use 2) Disposable Test Tube 3) Used Weighing Paper 4) Leftover solid organic compound
1) Sharps Container 2) Broken Glass Container 3) Regular Trash 4) Solid Chemical Waste
Pre Lab 2: Where do the following items need to be disposed after carrying out the melting point experiment? 1) Glass pipette after use 2) Disposable Test tube 3) Used filter Paper 4) Ethanol filtrate
1) sharps container 2) Broken glass container 3) Regular Trash 4) Solvent/Liquid Waste
Pre-Lab 8: What is the Molecular Weight, Melting point, Solubility, Boiling Point, density, grams used, and moles used of the following reagents? Table of Reactants: 1) Benzil 2) Ethanol 3) Sodium Borohydride 4) Water What is the Molecular Weight, Melting point, Solubility, Boiling Point, density, and theoretical yield of the following reagents? Table of Products: 1) R,R and S,S Hydrobenzoin 2) meso- hydrobenzoin 3) R and S benzoin
Reactants: 1) 210.23 g/mol, 94-95C, in water: insoluble and ethanol: soluble, 346-348C, 1.521 g/mL, 0.050g, 0.000238 2) 46.07g/mol, 113-115C, in water: miscible, 78.37C, 0.789g/mL, 0.395g, 0.00857 3) 37.8278g/mol, 37C, soluble in water and ethanol and insoluble in hydrocarbons, 932C, 1.035g/mL, 0.010 g, 0.000264 4) 18.02g/mol, 0C, Water: yes, 100C, 1.0g/mL, 0.5g, 0.0278 Products: 1) 214.26 g/mol, 120C, soluble in ethanol and hot alcohol, 314.4C, 1.0781g/mL 2) 214.25 g/mol, 136-137C, soluble in ethanol and hot alcohol, 137-139C, 0.025g/mL, 0.05099 3) 212.24 g/mol, 134-136C, in water: soluble and slightly soluble in ethanol, 1.31 g/mL
Pre-Lab 9: What is the Molecular Weight, Melting point, Solubility, Boiling Point, density, grams used, and moles used of the following reagents? Table of Reactants: 1) Cholesterol 2) MCPBA 3) Methylene Chloride What is the Molecular Weight, Melting point, Solubility, Boiling Point, density, and theoretical yield of the following reagents? Table of Products: 1) 5a-6a-epoxycholestan-3B-ol 2) 5b-6b-epoxycholestan-3B-ol 3) 3-chlorobenzoic acid
Table of Reactants: 1) 386.65 g/mol, 148C, in water: 0.095mg/L, 360C, 1.052 g/mL, 0.065g, 0.00017 2) 172.57 g/mol, 92-94C, insoluble in water and Soluble in: dichloromethane, Chloroform, ethyl acetate, benzene, and ether, 302.76C, 1.482 g/mL, 0.004g, 0.00023 3) 84.93 g/mol, -96.7C, Miscible in ethyl acetate, alcohol, hexanes, benzene, CCL4, diethyl ether, and CHCl3, 39.6C, 1.33 g/mL, 1.064g, 0.0125 Table of Products: 1) 402.653 g/mol, 147C, in water: somewhat miscible, 464.74C, 0.993 g/mL, 0.068 2) 402.653 g/mol, 147C, in water: somewhat miscible, 464.74C, 0.993 g/mL, 0.068 3) 156.57 g/mol, 155.5C, in water: 0.45mg/mL, 275C, 1.49g/mL, 0.0313
Pre-Lab 4: What character of the actual elements (aluminum, silicon, oxygen) present in alumina and silica cause the stationary phase to be very polar?
The covalent network between the alumina and silica makes it a very polar surface so it becomes electropositive to become attractive to the electronegative part of the oxygen
Pre- Lab 3: What is the vapor pressure of sugar solution dependent on?
The number of water molecules present in a given volume
Pre-lab 2: In the solvent Pair experiment that is being carried out with the solid that is being recrystallized, why do you NOT have to worry about sudden vigorous boiling of the crystal solution when you add the second solvent to the solution
The second solvent has the higher boiling point than the first solvent
Pre-Lab 8: Pure R,R-hydrobenzoin (side product of meso-hydrobenzoin) has a melting point of 148°C. a) What do you expect the melting point of pure S,S-hydrobenzoin (another side product of meso-hydrobenzoin) to be? b) Do you expect the racemic mixtures of these enantiomers to have the same or different melting points as the pure enantiomers?
a) 148 degrees b) different
Pre-Lab 7: In order to minimize forming a mixture of products in the reactions in the question above (a) which reactant would you use excess of? (b) Why?
a) 2,2-dimethylpropanal b) it has no alpha hydrogens
Pre-Lab 8: If you had carried out a TLC on the reaction mixture in this experiment, you would have used a 2:1 mixture of hexanes/ethyl acetate as your eluent. a) From Table 8.3 in the TLC chapter, is your eluent made up of mostly polar or nonpolar solvent? b) From the the TLC background and theory lecture, besides proper balance of polarity, what is the requirement for the pair of solvents? c) You are using 2:1 hexanes/ethyl acetate to develop the TLC plate and measure the distance the sample(s) travelled. Would the distances travelled by the sample(s) increase or decrease if you: i) added more ethyl acetate to the eluent__________ ii) added more hexanes to the eluent _______
a) nonpolar b) miscible i) increase ii) decrease
Pre-Lab 9: Compare and Contrast the travelling of eluent in TLC versus column chromatography a) TLC: solvent ________ the plate by ________ b) Column chromatography: Solvent _______ the column filled with absorbent
a) rises up; capillary action b) flows down
Pre Lab 6: In the synthesis of isobutyl propionate excess propanoic acid is used in the reaction. a) What purpose does the excess acid serve? b) What does this indicate with regards to the relative costs of the two starting materials in this synthesis?
a) shift equilibrium towards formation of ester b) Propanoic acid is the cheaper reagent