Chemistry: A Molecular Approach
3rd Edition
ISBN: 9780321809247
Author: Nivaldo J. Tro
Publisher: Prentice Hall
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Chapter 4, Problem 19E
Interpretation Introduction
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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 4 Solutions
Chemistry: A Molecular Approach
Ch. 4 - Prob. 1SAQCh. 4 - Q2. Sodium and chlorine react to form sodium...Ch. 4 - Prob. 3SAQCh. 4 - Prob. 4SAQCh. 4 - Prob. 5SAQCh. 4 - Prob. 6SAQCh. 4 - Prob. 7SAQCh. 4 - Prob. 8SAQCh. 4 - Prob. 9SAQCh. 4 - Q10. What is the net ionic equation for the...
Ch. 4 - Q11. What is the net ionic equation for the...Ch. 4 - Q12. What is the net ionic equation for the...Ch. 4 - Prob. 13SAQCh. 4 - Prob. 14SAQCh. 4 - Prob. 15SAQCh. 4 - 1. What is reaction stoichiometry? What is the...Ch. 4 - Prob. 2ECh. 4 - Prob. 3ECh. 4 - Prob. 4ECh. 4 - 5. What is molarity? How is it useful?
Ch. 4 - 6. Explain how a strong electrolyte, a weak...Ch. 4 - 7. Explain the difference between a strong acid...Ch. 4 - Prob. 8ECh. 4 - Prob. 9ECh. 4 - Prob. 10ECh. 4 - Prob. 11ECh. 4 - Prob. 12ECh. 4 - Prob. 13ECh. 4 - Prob. 14ECh. 4 - 15. What is an acid–base reaction? Give an...Ch. 4 - 16. Explain the principles behind an acid–base...Ch. 4 - 17. What is a gas-evolution reaction? Give an...Ch. 4 - 18. What reactant types give rise to gas-evolution...Ch. 4 - Prob. 19ECh. 4 - Prob. 20ECh. 4 - Prob. 21ECh. 4 - Prob. 22ECh. 4 - 23. In a redox reaction, which reactant is the...Ch. 4 - Prob. 24ECh. 4 - Prob. 25ECh. 4 - Prob. 26ECh. 4 - 27. Calculate how many moles of NO2 form when each...Ch. 4 - 28. Calculate how many moles of NH3 form when each...Ch. 4 - Prob. 29ECh. 4 - Prob. 30ECh. 4 - Prob. 31ECh. 4 - Prob. 32ECh. 4 - 33. For each of the reactions, calculate the mass...Ch. 4 - 34. For each of the reactions, calculate the mass...Ch. 4 - 35. For each of the acid–base reactions, calculate...Ch. 4 - Prob. 36ECh. 4 - 37. Find theFor the following reaction, determine ...Ch. 4 - 38. Find the limiting reactant for each initial...Ch. 4 - Prob. 39ECh. 4 - Prob. 40ECh. 4 - Prob. 41ECh. 4 - 42. Calculate the theoretical yield of product (in...Ch. 4 - Zinc sulfide reacts with oxygen according to the...Ch. 4 - 44. Iron(II) sulfide reacts with hydrochloric acid...Ch. 4 - Prob. 45ECh. 4 - Prob. 46ECh. 4 - 47. Iron(III) oxide reacts with carbon monoxide...Ch. 4 - 48. Elemental phosphorus reacts with chlorine gas...Ch. 4 - 49. Lead ions can be precipitated from solution...Ch. 4 - Prob. 50ECh. 4 - Prob. 51ECh. 4 - Prob. 52ECh. 4 - 53. Calculate the molarity of each solution.
a....Ch. 4 - Prob. 54ECh. 4 - 55. What is the molarity of NO3– in each...Ch. 4 - Prob. 56ECh. 4 - Prob. 57ECh. 4 - 58. What volume of 0.200 M ethanol solution...Ch. 4 - Prob. 59ECh. 4 - Prob. 60ECh. 4 - 61. If 123 mL of a 1.1 M glucose solution is...Ch. 4 - 62. If 3.5 L of a 4.8 M SrCl2 solution is diluted...Ch. 4 - 63. To what volume should you dilute 50.0 mL of a...Ch. 4 - 64. To what volume should you dilute 25 mL of a...Ch. 4 - Prob. 65ECh. 4 - 66. Consider the reaction:
Li2S(aq) + Co(NO3)2(aq)...Ch. 4 - 67. What is the minimum amount of 6.0 M H2SO4...Ch. 4 - Prob. 68ECh. 4 - 69. A 25.0-mL sample of a 1.20 M potassium...Ch. 4 - Prob. 70ECh. 4 - Prob. 71ECh. 4 - Prob. 72ECh. 4 - Prob. 73ECh. 4 - Prob. 74ECh. 4 - Prob. 75ECh. 4 - 76. Complete and balance each equation. If no...Ch. 4 - Write a molecular equation for the precipitation...Ch. 4 - 78. Write a molecular equation for the...Ch. 4 - Prob. 79ECh. 4 - 80. Write balanced complete ionic and net ionic...Ch. 4 - Prob. 81ECh. 4 - Prob. 82ECh. 4 - 83. Write balanced molecular and net ionic...Ch. 4 - Prob. 84ECh. 4 - Prob. 85ECh. 4 - Prob. 86ECh. 4 - Prob. 87ECh. 4 - 90. A 30.00-mL sample of an unknown H3PO4 solution...Ch. 4 - Prob. 89ECh. 4 - Prob. 90ECh. 4 - Prob. 91ECh. 4 - Prob. 92ECh. 4 - Prob. 93ECh. 4 - Prob. 94ECh. 4 - Prob. 95ECh. 4 - Prob. 96ECh. 4 - Prob. 97ECh. 4 - Prob. 98ECh. 4 - Prob. 99ECh. 4 - Prob. 100ECh. 4 - 103. People sometimes use sodium bicarbonate as an...Ch. 4 - 104. Toilet bowl cleaners often contain...Ch. 4 - Prob. 103ECh. 4 - Many home barbeques are fueled with propane gas...Ch. 4 - Prob. 105ECh. 4 - Prob. 106ECh. 4 - Prob. 107ECh. 4 - 110. A hydrochloric acid solution will neutralize...Ch. 4 - 111. Predict the products and write a balanced...Ch. 4 - 112. Predict the products and write a balanced...Ch. 4 - Prob. 111ECh. 4 - Prob. 112ECh. 4 - Prob. 113ECh. 4 - Prob. 114ECh. 4 - 117. The nitrogen in sodium nitrate and in...Ch. 4 - 118. Find the volume of 0.110 M hydrochloric acid...Ch. 4 - Prob. 117ECh. 4 - 120. We prepare a solution by mixing 0.10 L of...Ch. 4 - Prob. 119ECh. 4 - Prob. 120ECh. 4 - Prob. 121ECh. 4 - 124. An important reaction that takes place in a...Ch. 4 - 125. A liquid fuel mixture contains 30.35% hexane...Ch. 4 - 126. Titanium occurs in the magnetic mineral...Ch. 4 - Prob. 125ECh. 4 - Prob. 126ECh. 4 - Prob. 127ECh. 4 - Prob. 128ECh. 4 - 131. Recall from Section 4.6 that sodium carbonate...Ch. 4 - 132. Lead poisoning is a serious condition...Ch. 4 - Prob. 131ECh. 4 - Prob. 132ECh. 4 - Prob. 133ECh. 4 - Prob. 134ECh. 4 - Prob. 135ECh. 4 - Prob. 136ECh. 4 - Prob. 137ECh. 4 - Consider the generic ionic compounds with the...
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