Web Activities
UNIT 4: CHEMICAL SYSTEMS AND EQUILIBRIUM
Chapter 7 – Chemical Systems and Equilibrium
Section 7.1 Questions
p. 438
Question 11
Many of the nutrients in digested food, such as the carbohydrate
fructose, area absorbed into the cells of the small intestine by diffusion.
This occurs because, after a meal rich in carbohydrates, the concentration
of fructose in solution in the intestinal tract is higher than the concentration
inside the surrounding cells.
(a) Will diffusion result of the absorption of all fructose
molecules from the digesting food travelling through the intestine?
Explain.
(b) Consult a general biology textbook or conduct Internet research
to determine how cells ensure that they absorb the maximum possible
amount of nutrients.
How Nutrients and Other Molecules Get into Cells
This news article gives a general description of how cells absorb nutrients and molecules.
Cellular
Metabolism
This page provides a good overview of basic cellular metabolism.
Cellupedia
This is another page that explains cellular processes.
Practice
p. 458-459
Question 8
The digestion of some high-protein foods, such as red meat,
beans, lentils, and shell-fish, releases uric acid, HC5H3N4O3(aq), which
ionizes into hydrogen ions, H+(aq), and urate ions, C5H3N4O3-(aq), in
the bloodstream. People whose kidneys do not function properly cannot
excrete urate in the blood. This sometimes leads to a painful form of
arthritis known as gout, characterized by the formation of tiny needle-like
crystals of sodium urate, NaC5H3N4O3(s), in joints and tissues, according
to the equation
NaC5H3N4O3(s) ?(equilibrium)
Na+(aq) + C5H3N4O3-(aq)
a. Suppose you were a nutritionist. What advice could you
give to your patients who suffer from gout? Explain why following
the advice would be effective.
b. Many women take calcium supplements on a daily basis to prevent
the loss of bone mass (a condition known as osteoporosis). If a woman
suffering from osteoporosis has gout too, she may develop kidney stones
(which can consist of calcium urate). Write a chemical equilibrium
equation for this reaction and explain why this happens.
c. Research and report on other non-dietary treatments of gout.
Gout
This web page, sponsored by the Arthritis Foundation, provides detailed
information about gout, its symptoms, causes, and treatment options.
Gout
Center
This site provides information about gout, its symptoms, its causes,
and specific drugs that are used in its treatment.
Gout
and Pseudogout
This page from MEDLINEplus lists a number of links about gout, its diagnosis,
prevention, and treatment.
Section 7.3 Questions
p. 460
Question 9
Hydrogen sulfide is a foul-smelling and toxic byproduct of
the processing of crude oil and natural gas. One method to recover H2S
so that it does not contaminate the environment is known as the Claus
process, which involves the following reaction:
2 H2S(g) + SO2(g) [eqm symbol]
3S(s) + 2 H2O(g) + heat
The Claus process is capable of removing up to 95% of the sulfur
emissions from petroleum-processing plants.
a. Research and report on the Claus process.
b. Describe why it is advantageous to remove the sulfur from the process
as quickly as it forms.
Exploring
the Claus Process
This page provides simplified flow diagrams of the typical Claus process,
for removing sulfur emissions from petroleum-processing plants, as well
as a summary of the chemistry involved.
Converting
Hydrogen Sulfide by the Claus Process
This page provides simplified flow diagrams of the typical Claus process,
for removing sulfur emissions from petroleum-processing plants, as well
as a summary of the chemistry involved.
Section 7.1 Questions
p. 460
Question 10An air purification system involving lithium hydroxide,
LiOH, was used in NASA’s Apollo missions to the moon. LiOH absorbs
carbon dioxide.
2 LiOH(s) + CO2(g) [eqm symbol]
Li2CO3(s) + H2O (l)
Use Le Chatelier’s principle to explain why the amount
of time astronauts can spend in a spacecraft is limited.
MSDS Data Sheet
Try to pick out useful information from this Material Safety Data Sheet.
Le Chatalier's Principle
This page summarizes Le Chatalier's Principle.
How
to Walk, Talk, and Breathe on Mars
This document discusses design specifications for a proposed space suit
for the exploration of Mars. A discussion of the carbon dioxide scrubbing
unit containing lithium hydroxide is included.
p. 460
Question 11
When the Olympic Games were held in Mexico in 1968, many athletes
arrived early to train in the higher altitude (2.3 km above sea level)
and lower atmospheric pressure of Mexico City. Exertion at high altitudes,
for people who are not acclimatized, may make them “lightheaded”
from lack of oxygen. A similar effect occurred at the 2002 Winter Olympics
in Salt Lake City, Utah (1.3 km above sea level). Use the theory of
dynamic equilibrium to explain this observation. How are people who
normally live at high altitudes physiologically adapted to their reduced-pressure
environment?
International
Altitude-Training Symposium
This page provides background to the effects on altitude on training,
the benefits of high altitude training, and suggestions for how to train
at high altitudes.
Altitude
Illness
This page describes what happens to people when they move to higher altitudes, including the physiological changes that take place.
Three High-Altitude Peoples, Three Adaptations to Thin Air
This page describes how several groups have adapted to living at high altitudes.
p. 460
Question 12
Hemoglobin, Hb, a protein molecule found in red blood cells,
attracts and binds inhaled oxygen, which can then be transported throughout
the body.
Hb(aq) + O2(aq) [eqm symbol]
HbO2(aq)
Carbon monoxide, CO(g), binds more readily to hemoglobin than
oxygen and can displace oxygen according to this equilibrium:
HbO(aq) + CO(g) [eqm symbol]
HbCO(aq) + O2(g)
K=200 at 37ºC
Consider this scenario:
A patient, unconcious due to suspected carbon monoxide poisoning, has
just been brought to the hospital emergency ward where you are the doctor
in charge. Based on your knowledge if Le Chatelier’s principle,
what treatment would you recommend?
The
Hidden Danger of Carbon Monoxide Poisoning
This page describes the symptoms, medical consequences, causes, treatments
and prevention suggestions of carbon monoxide poisoning.
Carbon
Monoxide and Physiological Effects
This page gives a detailed explanation of how carbon monoxide affects the body.
Practice
p. 462
Question 5
a. Ammonia, produced by the Haber process, can be oxidized
to nitric acid, the raw material used in the manufacture of explosives.
Perform library or Internet research to determine the most common types
of explosives produced with nitric acid.
b. Draw structural formulas for the three most common nitrogen-based
explosives. What are the specific uses of each?
c. Write the chemical equation that describes a nitroglycerine explosion.
Why is this reaction explosive?
d. What is gun cotton? What are its uses? How is it made?
Nitric Acid General Information
This page has a good deal of information regarding nitric acid.
Nitric Acid
This page provides general background information about high explosives.
A chemical equation for the decomposition of nitroglycerine is given.
Explosives
This page provides an interesting graphic history of the development
of explosives as well as a brief summary of how explosives can be detected.
Section 7.4 questions
p. 462
Question 2
The Haber process requires nitrogen and hydrogen as reactants.
(a) Suggest reasonable sources for each of these elements.
(b) Conduct library and/or Internet research to learn how modern ammonia
production facilities obtain pure hydrogen nitrogen for the process.
Haber
Process Research Site
This page provides background into the history of the Haber process,
the raw materials it requires, the reaction conditions required, and
the importance of nitric acid to the production of fertilizers.
Production
of Ammonia
This site explains how ammonia is produced and how production of it is changing in the U.S.
p. 462
Question 3
To be used by growing plants, elemental nitrogen must first
be converted into another form (such as ammonia) in a natural process
called nitrogen fixation. The Haber process is synthetic nitrogen fixation.
(a) How do bacteria fix nitrogen naturally?
(b) Currently, which of the two processes, synthetic and natural,
fixes the most nitrogen.
(c) What problems have arisen from the dramatic increase in nitrogen
fixation in the last century? Pick one of these problems and suggest
some remedies.
The
Nitrogen Cycle and Nitrogen Fixation
The site gives a thorough summary of the role of nitrogen in the biosphere,
nitrogen fixation, nitrogen-fixing organisms, and the nitrogen cycle.
Problems
with Nitrogen Pollution
This site offers a good summary of the problems associated with nitrogen
pollution, the nitrogen cycle and how human activity has affected it.
Fertilizer
Consumption
This page provides graphics showing the dramatic rise in worldwide fertilizer
consumption.
Role
of Nitrogen in Plants
This document gives in depth background to the efficient use of fertilizers.
It covers the nitrogen cycle, soil chemistry, current practice in the
use fertilizers, and the production of fertilizers.
Nitrogen
Here is a general description of nitrogen and its uses.
Explore an Issue – Take a Stand: Can We Do Anything About Pollution?
p. 501
Proposition: The second law of thermodynamics makes pollution
an inevitable result of human activity. There’s nothing we can
do about it.
Conduct independent library or Internet research on both sides of the
issue.
a. Prepare an individual position paper on the issue.
Thermodynamics:
The Second Law
This site gives a graphic explanation of the second law of thermodynamics.
The
Second Law of Thermodynamics
The document gives a thorough summary of the second law of thermodynamics,
activation energy, and concludes with the link between the second law
of thermodynamics and pollution.
Chapter 7 review
p. 525
Question 21
The operation of a halogen lamp depends, in part, on the equilibrium
system
W(s) + I2(g) [eqm symbol] WI2(g)
Research the role of temperature in the operation of a halogen
lamp. For example, how is it possible for a halogen lamp to operate
with the filament at 2700°C when the tungsten would normally decompose/oxidize
at this high temperature? Is such a high operating temperature desirable?
How
Do Halogen Lights Work?
This page describes how halogen lamps work, how they differ from standard
light bulbs differ, and why they are sometimes called “quartz
halogen”. It also describes how the equilibrium given in question
21 prolongs the life of the lamp.
The
Halogen Cycle in an Incandescent Lamp
This page provides very useful diagrams showing the operation of the
tungsten iodide equilibrium in a lamp.
p. 525
Question 23
Explain how equilibrium principles are applied to optimize
the industrial production of sulfuric acid.
Sulfuric
Acid
This page, compiled from Chemical and Engineering News, June 25, 2001
provides a good summary of the chemistry of sulfuric acid, including
its synthesis, environmental concerns and economic importance.
Sulfuric Acid 2
This page provides an explanation of the synthesis of sulfuric acid, along with some other interesting information.
