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Can you show me the calculations for trial 2 please

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A. Freezing Point of Cyclohexane (Solvent)
1. Mass of beaker, test tube (g)
128-11
2. Freezing point, from cooling curve co)
6.0
3. Instructor's approval of graph
B. Freezing Point of Cyclohexane plus Unknown Solute
Trial I
Trial 2
Trial 3
Unknown solute no.
(Parts B.I, 8.3)
(Part B.4)
( Part B.5)
1. Mass of beaker. test tube, cyclohexane (g)
137.06
2. Mass of cyclohexane (@)
8.95
3. Tared mass of added solute (e)
D.140
0.700
0. 140
4. Freezing point, from cooling curve ("()
ZO
LO
5, Instructor's approval of graph
Calculations
1. &, for cyclohexane ("C . ke/mol)
20.0
2. Freezing-point change, AT,(C)
S.0
4.0
3. Mass of cyclohexane in solution (kg)
0.00 895
0.00895
4. Moles of solute, total (mol)
0.20179
2:201 79
5. Mass of solute in solution, rosal (g)
0-14
10-34
6. Molar mass of solute (exmol)
78.1.12
152-46
268-15
7. Average molar mass of solute (g/mol)
166. 273
Data Analysis, B
8. Standard deviation of molar mass
Data Analysis, C
9. Relative standard deviation of molar mass ("RSD)
Data Analysis, D
"Show calculation(s) for Trial 2 on the next page.
Experiment 14 197

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mansmitted without publisher's prior permission. Violators will be prosecuted,
"Calculations for Trial 2
A. Cyclohexane
B. Cyclohexane + Unknown Solute
Time
Temp
Trial
Trial
Trial 3
Time
Temp
Time
Temp
Time
Temp
IS
15
15
15
IS
16
9.0
4S
G.0
70
LD
75
75
7,0
75
7.0
40
1.O
5.0
7.0
105
D.0
( Zo
7.0
LO
-0.50
135 1
h.D
135
135
-1-0
Continue recording data on your own paper and submit it with the Report Sheet.
Laboratory Questions
Circle the questions that have been assigned.
1. Part A.3. Some of the cyclohexane solvent vaporized during the temperature versus time measurement. Will this loss
of cyclohexane result in its freezing point being recorded as too high, too low, or upaffected" Explain,
2. Part A.3. The digital thermometer is miscalibrated by +D.15'C over its entire range. If the same thennometer is used in
Part B.2, will the reported moles of solute in the solution be too high, too law, or unaffected? Explain.
3. Part B.I. Some of the solid salute adheres to the side of the test babe during the freezing point determination of the
solution in Part B.2. As a result of the oversight, will the reported molar mass of the solute be too high, too law, or
unallected Explain.
4. Part B.2. Some of the cyclohexane solvent vaporized during the temperature versus time measurement. Will this loss
of cyclohexane result in the freezing point of the solution being recorded as too high, too low, or unaffected? Explain.
5. Part B.2. The solute dissociates slightly in the solvent. How will the slight dissociation affect the reported molar mass
of the solute-too high, too low, or unaffected? Explain.
"6. Part B.3. Figure 14.3. The temperature versus time data plot (Figure 14.3) shows no change in temperature at the
freezing point for a pure solvent: however, the temperature at the freezing point for a solution steadily decreases until
the solution has completely solidified. Account for this decreasing temperatures,
7. Part C.I. Interpretation of the data plots consistently shows that the freezing points of three solutions are too high. As a
Explain.
result of this "misreading of the data," will the reported molar mass of the solute be too high, too low, or unaffected?
198 Molar Mass of a Solid

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