Fall 2015 -Lab 1-10- Lab Final prep guide - Chemistry 201 ...

Chemistry 201 (Fall 2014)
Lab Final Study Guide
Please go over
• Lab notes on Ub learns and Lab manual notes
• Pre lab quiz and post lab questions
• Lab reports and lab note books
• You will need to know
a. the procedure for all the experiments
b. All chemical Reactions involved (including ones for chemical tests) as well as the reaction
mechanisms
c. chemical structures of substances used and prepared.
d. Reasons for using a particular or technique in a lab e.g why did we perform a distillation in lab6
or why do we use bleach in lab 9?
e. Calculations : density, actual yield, theoretical , percent yield, R f , atom economy, reaction
efficiency etc, conversions of mass to volume, and moles from mass etc

Dates Lab #: EXPERIMENT
Sept 21-
26
Lab 2: Learning Basic Operations [Lehman Exp. 1 page 2]
Sept 28-
Oct 3
Lab 3: Separating the Components of Panacetin [Lehman Exp. 2 page 10]
Oct 5-
10
Lab 4:Identifying the Constituents of Panacetin [Lehman Exp. 3 page 18]
Oct 12-
17
Lab 5: Properties of organic compounds -Handout on UB learns.
Oct 19-
24
Lab 6: Synthesis of Salicylic acid (All parts except IR & NMR)
Oct 26-
31
Lab 7 Preparation of 2-chloro-2-methylbutane–Lehman Page xvii
Nov 02-
07
Lab 8: Separation of Unknown by Flash Column Chromatography-Lehman
Nov 9-
14
Lab 9: Dehydration of 4-Methylcyclohexanol [Lehman Exp. 21 page 73]
Nov 16-
21
Lab 10: A Diels-Alder Synthesis of 9,10-Dihydroanthracene-9,10 α, β —succinic acid Anhydride

Sodium benzoate ( SB ) Benzoic acid ( BA )
(MW = 144.1 g/mol) (MW = 122.1 g/mol)
C
6
H
5
COONa + HCl → C
6
H
5
COOH + NaCl
Calculations
X g SB x 1 mol SB/ 144.1 g SB = Y mol SB
1:1 molar ratio SB:BA, therefore… Y mol SB= Z mol BA
Z mol BA x 122.1 g BA/1 mol BA = theoretical yield 0
actual Yield = amount of product (BA) in gms recovered from the reaction ield.34 g BA
Percent yield = actual yield/theoretical yield x 100
Sample: 3.8 grams of benzoic acid ( BA )(M.W = 122.1g/mol) was obtained on precipitation of 5 grams of sodium benzoate- SB (M.W =
144.1g/mol) using Conc. HCl Calculate the expected theoretical yield (T.Y) and % yield of benzoic acid. Show all your work
Answer : Using MW, convert 5 g SB into moles, 1 mole =144.1 g hence 5 g SB = 0.034 moles .
0.034 moles should yield 0.034 moles of BA , this is the TY of BA
convert moles of BA into gms, 0.034 x 122.1 = 4.236 g (TY) % yield =AY÷TY x 100 = 3.8 ÷ 4.24 x 100 = 89.6 %
Lab 2: Learning Basic Operations [Lehman Exp 1 page 2]
HCl
HO
O
O
O
Na

Density of Unknown
Identify an unknown organic D that has the following mass/volume data. Prepare a graph from the data below, draw the best
straight line through the data points. From the slope of the graph calculate the density of the liquid ( use the chart of densities
provided ) up to three decimal places.
ANSWER: Slope is 0.8857 which is the density,
unknown liquid D is Ethyl Acetate closest value to 0.9
Mass(with vial D) Liquid volume Liquid mass
26.51 0 0
26.71 0.25 0.20
26.94 0.50 0.43
27.15 0.75 0.64
27.39 1.00 0.88
27.61 1.25 1.10
Substance Density literature
value
Pentane 0.626
Hexane 0.654
Acetone 0.791
Ethanol 0.789
Propanol 0.803
Ethyl Acetate 0.902
SOLUTION
2. A) What is the density of Unknown A if 5 ml weighs 10 gm.