Chemistry for Changing Times
14th Edition
ISBN: 9780134212777
Author: John W. Hill; Terry W. McCreary
Publisher: Pearson Education (US)
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Question
Chapter 2, Problem 4RQ
Interpretation Introduction
Interpretation:
Boyle’s contributions to modern chemistry should be mentioned.
Concept Introduction:
Robert Boyle was an Anglo-Irish scientist who made notable contributions to modern chemistry.
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Students have asked these similar questions
On the next page is an LC separation of the parabens found in baby wash. Parabens are
suspected in a link to breast cancer therefore an accurate way to quantitate them is desired.
a. In the chromatogram, estimate k' for ethyl paraben. Clearly indicate what values you used for
all the terms in your calculation.
b. Is this a "good" value for a capacity factor? Explain.
c. What is the resolution between n-Propyl paraben and n-Butyl paraben? Again, indicate clearly
what values you used in your calculation.
MAU
| Methyl paraben
40
20
0
-2
Ethyl paraben n-Propyl paraben
n-Butyl paraben
App ID 22925
6
8
min
d. In Figure 4, each stationary phase shows some negative correlation between plate count
and retention factor. In other words, as k' increases, N decreases. Explain this relationship
between k' and N.
Plate Count (N)
4000
3500
2500
2000
1500
1000
Figure 4. Column efficiency (N) vs retention factor (k') for 22
nonionizable solutes on FMS (red), PGC (black), and COZ (green). 3000
Eluent compositions (acetonitrile/water, A/W) were adjusted to obtain
k' less than 15, which was achieved for most solutes as follows: FMS
(30/70 A/W), PGC (60/40), COZ (80/20). Slightly different
compositions were used for the most highly retained solutes. All
columns were 50 mm × 4.6 mm id and packed with 5 um particles,
except for COZ, which was packed with 3 um particles. All other
chromatographic conditions were constant: column length 5 cm,
column j.§. 4.6 mm, flow rate 2 mL/min, column temperature 40 °C,
and injection volume 0.5 μL
Log(k'x/K'ethylbenzene)
FMS
1.5
1.0
0.5
0.0
ཐྭ ཋ ཤྩ བྷྲ ;
500
0
5
10…
f. Predict how the van Deemter curve in Figure 7
would change if the temperature were raised
from 40 °C to 55 °C.
Figure 7. van Desmter curves in reduced coordinates for four
nitroalkane homologues (nitropropane, black; nitrobutane, red;
nitropentane, blue; and nitrohexane, green) separated on the FMS
phase. Chromatographic conditions: column dimensions 50 mm × 4.6
mm id, eluent 30/70 ACN/water, flow rates 0.2-5.0 mL/min, injection
volume 0.5 and column temperature 40 °C. No corrections to the
plate heights have been made to account for extracolumn dispersion.
Reduced Plate Height (h)
°
20
40
60
Reduced Velocity (v)
8. (2) A water sample is analyzed for traces of benzene using headspace analysis. The sample and
standard are spiked with a fixed amount of toluene as an internal standard. The following data are
obtained:
Ppb benzene
Peak area benzene
Peak area toluene
10.0
252
376
Sample
533
368
What is the concentration of benzene in the sample?
Chapter 2 Solutions
Chemistry for Changing Times
Ch. 2 - Prob. 1RQCh. 2 - Prob. 2RQCh. 2 - Prob. 3RQCh. 2 - Prob. 4RQCh. 2 - Cavendish found that water was composed of two...Ch. 2 - Prob. 6RQCh. 2 - Fructose (fruit sugar) is always composed of 40,0%...Ch. 2 - Outline the main points of Dalton's atomic theory,...Ch. 2 - Prob. 9RQCh. 2 - Prob. 10RQ
Ch. 2 - In the figure. the blue spheres represent...Ch. 2 - 12. a. How is Avogadro’s number linked with the...Ch. 2 - Prob. 13RQCh. 2 - Prob. 14RQCh. 2 - Prob. 15PCh. 2 - 16. An iron nail dissolves in a solution of...Ch. 2 - If you place a 400 g effervescent antacid pill...Ch. 2 - Prob. 18PCh. 2 - 19, Acetylene, used for welding, contains 24.02 g...Ch. 2 - 20. Nitrous oxide (N2O, "laughing gas") contains...Ch. 2 - Prob. 21PCh. 2 - Prob. 22PCh. 2 - Prob. 23PCh. 2 - Prob. 24PCh. 2 - When 18.029 of water is decomposed by...Ch. 2 - Prob. 26PCh. 2 - Prob. 27PCh. 2 - Prob. 28PCh. 2 - Prob. 29PCh. 2 - Prob. 30PCh. 2 - 31. Use Dalton's atomic theory to explain what is...Ch. 2 - Prob. 32PCh. 2 - Hydrogen and oxygen combine in a mass ratio of...Ch. 2 - Prob. 34PCh. 2 - Prob. 35PCh. 2 - A compound containing only oxygen and rubidium has...Ch. 2 - 37. A sample of an oxide of tin with the formula...Ch. 2 - 38. Consider three oxides of nitrogen, X, Y, and...Ch. 2 - Prob. 39PCh. 2 - Prob. 40PCh. 2 - Prob. 41PCh. 2 - Prob. 42PCh. 2 - Prob. 43PCh. 2 - Prob. 44PCh. 2 - A blue solid called azulene is thought to be a...Ch. 2 - Prob. 46PCh. 2 - Prob. 47APCh. 2 - Prob. 48APCh. 2 - Prob. 49APCh. 2 - Prob. 50APCh. 2 - 51. See Table 2.1 . Another compound of nitrogen...Ch. 2 - Prob. 52APCh. 2 - Prob. 53APCh. 2 - Prob. 54APCh. 2 - Prob. 55APCh. 2 - Prob. 56APCh. 2 - Prob. 57APCh. 2 - Prob. 58APCh. 2 - Prob. 2.1CTECh. 2 - When water is electrolyzed, from each one molecule...Ch. 2 - A health-food store has a large display of...Ch. 2 - Prob. 2.4CTECh. 2 - Prob. 2.5CTECh. 2 - Prob. 2.6CTECh. 2 - Prob. 1CGPCh. 2 - Prob. 2CGPCh. 2 - Prob. 3CGPCh. 2 - Prob. 4CGPCh. 2 - Prob. 5CGPCh. 2 - Materials Needed: Alka-Seltzer tablets (8) 1/4 cup...Ch. 2 - Materials Needed: Alka-Seltzer tablets (8) 1/4 cup...Ch. 2 - Prob. 3CHQ
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