CHEM 120 Week 6 Laws of Thermodynamics- Chamberlain College Atlanta
WEEK 6
Laws of Thermodynamics
1. Which of these would you classify as an exothermic
... [Show More] process?
a. Ice melting
b. Wood burning
c. Evaporation of alcohol
d. Photosynthesis
Heat is released in exothermic reactions , like burning wood, and absorbed in endothermic
reactions.
2. Which of these processes would not be possible?
a. Energy spontaneously flows from a hot object to a cool one
b. Two liquid chemical are mixed together and the temperature of the mixture rapidly cools
c. Energy is transferred in a chemical reaction
Energy cannot be created or destroyed in a chemical reaction.
3. For each of the situations, determine if the observed behavior is a consequence of the first or
second Law of Thermodynamics:
Situation, Select Law
As a rocket takes off, energy in the fuel is converted into kinetic energy, heat, and light., ---
1st Law of Thermodynamics, 2nd Law of Thermodynamics
An ice cube melts on a hot day., ---
1st Law of Thermodynamics, 2nd Law of Thermodynamics
On a hot day, you turn on the oven, causing the room to become even hotter., ---
1st Law of Thermodynamics, 2nd Law of Thermodynamics
Turning on a computer results in electricity being converted into mechanical work, heat, and light.,
---
1st Law of Thermodynamics, 2nd Law of Thermodynamics
The first law has to do with the transfer of energy from one form to another and the second law has
to do with the spontaneous and irreversible flow of energy from hot to cold. Examples of the 1st
Law are the conversion of rocket fuel into kinetic energy, heat, and light; and the electricity for a
computer into mechanical work, heat, and light. Examples of the 2nd Law are ice melting and room
heating from a working oven.
4. Match the reaction to the type:
Endothermic --- Photosynthesis, Chemical Ice Pack, Iron Melting, Methanol Evaporating.
Exothermic --- Water Freezing, Mixed Chemicals producing Heat, Water Condensing, Burning Gas
Iron melting, Two chemicals are mixed together, producing heat, Methanol evaporating , Photosynthesis,
Burning gasoline, Water condensing on a cool surface, Water freezing, A chemical ice pack
Endothermic Reactions: Photosynthesis, Chemical Ice Pack, Iron Melting, Methanol Evaporating.
Exothermic Reactions: Water Freezing, Mixed Chemicals producing Heat, Water Condensing,
Burning Gas
5. When a cool penny is placed in a hot car in the summer, the heat flows spontaneously from the
interior of the car to the Penny, in an illustration of the 2nd Law of thermodynamics.
Penny, interior of the car
Penny, interior of the car
1
st, 2nd
Heat flowing from the hot car interior into the cool penny is an example of the
2nd Law of Thermodynamics.
6. Sort the following process as exothermic or endothermic:
Endothermic --- Carbon dioxide converts from a solid to a gas, A pair of chemicals are
mixed together in a beaker and the beaker becomes cold,
Exothermic --- Wood burns in a bonfire , Your body digests food for energy,
generating excess heat , On a humid day water condenses on a cool surface
Wood burns in a bonfire, Your body digests food for energy, generating excess heat,
On a humid day water condenses on a cool surface, Carbon dioxide converts from a
solid to a gas, A pair of chemicals are mixed together in a beaker and the beaker
becomes cold
Energy from system to surroundings is exothermic and energy from
surroundings to system in endothermic. Thus, Endothermic reactions are carbon
dioxide moving from a solid to a gas and mixing chemicals that become cold.
Exothermic reactions are burning wood, digesting food, and condensation.
7. When sodium hydroxide is dissolved in water within a beaker, you observe that
the beaker becomes warm. This situation illustrates:
a. The 2nd Law of Thermodynamics
b. The 1st Law of Thermodynamics
c. An exothermic reaction
5. Select all the following situations that you would classify as endothermic
processes:
a. Lava cools and becomes a solid
b. Hand sanitizer evaporating
c. Ammonium nitrate dissolves in water and the solution becomes cold
d. Butane combusts to give a flame in a lighter
The endothermic reactions are hand sanitizer evaporating and ammonium
nitrate dissolving and the solution becomes cold.
Radiation
8. Which of the following are types of electromagnetic radiation?
a. Alpha particles
b. Light
c. X-rays
d. Radio waves
Electromagnetic reactions do not have mass, so alpha particles are not
electromagnetic.
9. Which type of radiation would you consider ionizing radiation?
a. Gamma rays
b. Microwaves
c. Sound waves
d. Visible light
10. Ionizing radiation can alter the electron structure of an atom, causing an ion
to form. Gamma rays are ionizing radiation.
Which of the following procedures in healthcare involve the use of radiation to
take images?
a. Temperature measurements using thermometers
b. CT scans
c. Pulse measurements
d. X-ray
Radiation is used extensively in healthcare for imaging as well as treatment. CT
scans and X-rays both involve radiation.
11. Is the type of radiation ionizing or non-ionizing?
Ionizing --- Gamma rays, X-rays
Non-ionizing --- Microwaves, Infrared, Microwaves, Infrared, Visible light
Microwaves, Infrared, X-rays, Visible light, Gamma rays, Radio waves
Ionizing radiation is higher in energy with shorter wavelengths while nonionizing radiation is lower in energy with longer wavelengths. X-rays and
Gamma rays are ionizing; Microwaves, infrared, visible light, and radio waves
are non-ionizing.
12. Classify the sources of radiation as ionizing or non-ionizing:
Ionizing --- CT scan, High energy UV lamp, Radon, The sun
Non-ionizing --- Microwave ovens, Cell phones
The sun
Microwave ovens
High energy UV lamp
CT scan
Radon
Cell phones
These are sources of radiation we can encounter in our day to day lives. Ionizing
radiation sources include high energy UV lamps, CT scans, the sun, and radon
gas. Non-ionizing sources include microwave ovens and cell phones.
13. Select all that would be considered sources of ionizing radiation.
a. Microwave ovens
b. Radon gas
c. Cell phones
d. CT scans
Recognizing the sources of radiation in your day to day life helps you to make
informed decisions about exposure. CT scans and radon gas are both sources of
ionizing radiation.
14. This type of radiation cannot remove electrons from atoms or molecules:
a. Particulate
b. Ionizing
c. Non-ionizing
d. Electromagnetic
Understanding the categories of radiation can help us to understand the
properties of different types of radiation. Non-ionizing radiation does not remove
electrons.
15. Determine if each of the following electromagnetic radiation types is ionizing
or non-ionizing:
Ionizing --- Gamma rays, Radio waves
Non-ionizing --- Infrared
Radio waves
Gamma rays
Infrared
Shorter wavelengths of light are high in energy and able to ionize while longer
wavelengths are lower in energy and not able to ionize. Infrared and radio waves
are both non-ionizing, while gammy rays are ionizing.
16. Radiation that has mass and can cause atoms and molecules to become
charged would be classified as:
a. Ionizing
b. Particulate
c. Electromagnetic
d. Non-ionizing
Understanding the categories of radiation can help us to understand the
properties of different types of radiation. Ionizing and particulate are both
classifications of radiation that can cause atoms and molecules to become
charged.
17. In the field of healthcare, ionizing radiation is used for:
a. CT scans
b. Measuring heart rate
c. Temperature measurements
d. Measuring blood pressure
Ionizing radiation is used for mainly imaging and radiation therapy in
healthcare. CT scans are a type of imaging used in healthcare and is ionizing.
Radioactive Isotopes
18. The atomic symbol of an element can be determined from the:
a. Atomic number
b. Atomic mass
c. Neutron number
d. Mass number
The atomic number gives the number of protons and determines the identity of
the atom.
19. Which of the subatomic particles below are found in the nucleus of the atom?
Select all that apply.
a. Proton
b. Neutron
c. Electron
d. Isotope
Protons and neutrons are found in the core of the atom.
20. Which type of radiation would penetrate most deeply into your body?
a. Beta electron
b. Gamma
c. Beta positron
d. Alpha
Gamma decay produces highly penetrating gamma particles.
21. Using the descriptions, match each to the correct isotopes
An isotope with a mass number of 131 and an atomic number of 53 ---
An isotope of phosphorus with a mass number of 32 ---
An isotope with an mass number of 53 and 25 protons ---
P3215, M3215n, Phosphorus-32, P1532, M53131n, I25131, Iodine-131, Iodine-53,
M2553n, Manganese-53, I53131
The correct isotopes are shown below for each description.
An isotope with a mass number of 131 and an atomic number of 53:
Iodine-131, I53131
An isotope of phosphorus with a mass number of 32:
Phosphorus-32, P1532
An isotope with an mass number of 53 and 25 protons:
Manganese-53, M2553n
22. Complete the radioactive decay by dragging the correct products of each
decay to the corresponding box.
Alpha decay of Pu-240 --- 23692U, 0-1βBeta (electron) decay of Cd-118 --- 1849In, 4a22+
Beta (positron) decay of In-98 --- 9848Cd, 01β+
01β+, 9848Cd, 11849In, 0-1β-, 23692U
Be sure to that both the top and bottom numbers have the same total on both
sides of the chemical reaction.
23. To wrap this up, you will be completing the table below, summarizing each
type of radioactive decay studied. Be sure to review the previous sections to
brush up on these and then use your understanding of the content to summarize.
Type of Process, Effect on mass number, Effect on atomic number
Alpha, No changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4, No
changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4
Beta electron, No changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4, No
changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4
Beta positron, No changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4, No
changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4
Gamma, No changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4, No
changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4
Electron capture, No changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4,
No changeIncrease by 1Decrease by 1Decrease by 2Decrease by 4
Type of Process Effect on mass number Effect on atomic number
Alpha Decrease by 4 Decrease by 2
Beta electron No change Increase by 1
Beta positron No change Decrease by 1
Gamma No change No change
Electron capture No change Decrease by 1
24. H80171g
undergoes alpha decay forming an alpha particle and
a. 17179Au
b. 17382Pb
c. 16778Pt
d. 17181Ti
We can determine the effect on the decay product by following the Law of
Conservation of Mass. When
H80171g
undergoes alpha decay, an alpha particle and
16778Pt
is formed.
25. Sort the following types of radiation in regard to their ability to penetrate the
human body from top (most) to least (bottom).
a. Alpha
b. Gamma
c. Beta Electron
Gamma
Beta Electron
Alpha
Understanding the penetrative properties of various types of radiation can help
us make important safety choices. The most penetrating type of radiation is
gamma, while the least is alpha.
26. Select all processes which cause a decrease in the atomic number of an
isotope.
a. Alpha decay
b. Beta Electron Decay
c. Gamma Decay
d. Electron Capture
e. Beta Positron Decay
The main ways to decrease atomic number are the removal of protons from the
nucleus or the conversion of a proton to a neutron. This could occur via alpha
decay, beta positron decay, and electron capture.
27. An proton absorbs an electron. What effect would you predict this to have in
an unstable isotope?
a. Increase in mass number
b. Decrease in mass number
c. Increase in atomic number
d. Decrease in atomic number
By understanding what is happening on a subatomic level, we can better predict
what is occurring in unstable isotopes. If a proton absorbs an electron in an
unstable isotope, you would see a decrease in the atomic number.
28. During a type of radioactive decay, the atomic number of an isotope increases
by one while the mass number is unchanged. I would expect that this is caused by
a. a proton combining with an electron
b. a proton becoming a neutron
c. protons and neutrons being ejected from the nucleus
d. a neutron becoming a proton
By understanding what is happening on a subatomic level, we can better predict
what is occurring in a specific radioactive decay process. When the atomic
number increases by one while the mass number is unchanged, a neutron has
become a proton.
29. Determine the products of the beta electron decay of Vanadium-52 (select all
that apply):
a. v2352→
b. S2148c
c. β++10
d. T2252i
e. C2452r
f. v2452
g. β--10
Beta decay increases the atomic number by 1.
30. If Magnesium-21 undergoes beta positron decay, I would expect the products
of this decay to be a positron and a
a. Alumium-22
b. Magnesium-20
c. Sodium-21
d. Sodium-20
We see a decrease of one for the atomic number in positron decay with no change
in the mass number.
Applications of Radiation
31. Which of the following technologies depend on radioactive isotopes to
function. Select all that apply.
a. Microwaves
b. Light bulbs
c. Nuclear power generation
d. PET Scans
PET scans and nuclear power generation both require radioactive isotopes to
function.
32. How many grams of a 4 grams sample of a radioactive material will remain
after two half-lives.
a. 4 grams
b. 2 grams
c. 1 gram
d. 0 grams
Each half-life decreases the amount currently remaining by 50%, so after two
half-lives, 4 grams would be 1 gram.
33. Answer the following questions related to half lives.
Question 1 / 3
A certain radioactive isotope has a half life of 2400 years. How many half lives have
past for a sample of this material collected 12,000 years ago? 5
Question 2 / 3
Oxygen-21 has a half life of about 3.5 seconds. How many half lives will have passed
after 14 seconds? 4
Question 3 / 3
Rn-221 has a half life of about 30 minutes. How many half lives have passed after 4
hours? 8
Question 1 Feedback
By dividing the time that has passed by the half life, we can determine the
number of half-lives that have passed. In this case 12,000/2,400=5.
Question 2 Feedback
The mass number of oxygen does not effect this equation and we divide the total
time by the half life as usual. In this case, 14 / 3.5 = 4.
Question 3 Feedback
We must make sure both units of time are the same before dividing. In this case,
4 hours x 60 minutes/hour = 240 minutes / 30 minutes = 8 half lives.
34. Answer the following questions about half life calculations.
Question 1 / 2
An unstable isotope has a half life of 3 days. How many kg of a 820 kg sample will
remain after 6 days? 205 kg
Question 2 / 2
Neodymium-161 h as a half life of about 500 ms. What % of a fresh sample of this
material would I have after 1 second? 25%
Question 1 Feedback
By dividing the time that has passed by the half life, we can determine the
number of half-lives that have passed. Then we just need to divide by two that
many times starting with the initial amount of sample. In this case, 6 / 3 = 2 half
lives. 820kg /2 = 410kg /2 = 205kg.
Question 2 Feedback
Make sure both units of time are the same before dividing the total time by the
half life as usual. Starting at 100 %, we divide by two for each half life. In this
case, there are 1000 ms /s, divided by 500ms = 2 half lives, so after two half lives
25% remains.
35. Au-180 has a half life of 8 seconds. How much of a 60 gram sample will
remain radioactive after 32 seconds?
a. 15 g
b. 30 g
c. 7.5 g
d. 3.75 g
After determining the number of half-lives that have passed, we simply divide
our starting amount by two for each half-life that has passed.
36. Rank the following applications of radioactive materials from highest
exposure (top) to least exposure (bottom).
a. Full body PET scan
b. Smoke detectors
c. Hand X-ray
d. Radiation therapy with gamma radiation
Radiation therapy with gamma radiation
Full body PET scan
Hand X-ray
Smoke detectors
By understanding risks, we can make informed choices. Highest exposure is
radiation therapy, followed by PET scan, X-ray, and smoke detectors.
37. Which of the following procedures would you expect to expose you to the least
amount of radiation?
a. PET scan
b. Insertion of radioactive seeds into your body as a cancer treatment
c. Gamma treatment of a tumor
d. Use of radioactive iodine to treat an overactive thyroid
In terms of radiation risk, nuclear imaging exposes you to less radiation overall
as compared to radiation therapy.
38. What % of a fresh sample of an unstable isotope with a half-life of 4 days
remain after 8 days. Assume you start with 100%.
a. 12.5 %
b. 25 %
b. 6.25 %
c. 50 %
After determining the number of half lives that have passed, we simply divide
our starting amount by two that many times.
Biological Polymers
39. In condensation reactions, what small molecule is produced as a by-product?
a. methane
b. hydrogen gas
c. water
d. acids
Water is the by-product of condensation reactions.
40. Answer the following questions about monomers and polymers.
Question 1 / 3
Monomers are small molecules used to build large molecules called polymers
Monomers, polymers
Monomers, polymers
Question 2 / 3
Which of the following is not an example of a polymer?
a. proteins
b. silk
c. cotton
d. rubber
e. styrene
Question 3 / 3
Condensation reactions are involved in _____ reactions.
a. transfer
b. combustion
c. anabolic
d. catabolic
e. neutralization
Question 1 Feedback
Monomers are small molecules used to build the large polymers.
Question 2 Feedback
Styrene is the monomer for Styrofoam polymer. Proteins, cotton, rubber, and silk
are all polymers.
Question 3 Feedback
Condensation reactions are involved in anabolic reactions because they build
polymers.
41. Click and drag to arrange the following by relative size, from smallest on the
top to largest on the bottom.
a. polymer
b. dimer
c. monomer
In order from smallest on top to largest on the bottom:
monomer
dimer
polymer
42. Answer the following questions about hydrolysis reactions.
Question 1 / 2
In condensation reaction, a water molecule is produced when a bond is Formed
In hydrolysis reactions, a water molecule is used when a bond is broken.
hydrolysis, condensation
formed, broken
hydrolysis, condensation
Formed, broken
Question 2 / 2
Determine if the statement applies to hydrolysis or condensation reactions.
Condensation Hydrolysis
Monomers are used to
form polymers yes
Polymers are broken
down to form monomers yes
Water is a product yes
Water is used as a
substrate yes
Question 1 Feedback
Water molecules are produced in condensation reactions, when bonds are
formed. Water molecules are used to break bonds in hydrolysis reactions.
Question 2 Feedback
Water molecules are produced in condensation reactions, when bonds are
formed. Water molecules are used to break bonds in hydrolysis reactions.
43. Examples of polymers include
a. proteins
b. carbohydrates
c. silk
d. all of the above
e. none of the above
All major macromolecules include carbohydrates, proteins, lipids, and nucleic
acids are polymers, as are rubber, silk, cotton, and plastics.
44. Select the letter next to the circled portion of the molecule that will react in a
condensation reaction.
A
B
C
D
Carboxylic acids (-COOH) can react in condensation.
45. _____ are larger than _____.
a. Monomers / polymers
b. Monomers / dimers
c. Dimers / monomers
d. Dimers / polymers
Dimers are made from two monomers, so they are larger than monomers.
46. Determine if the statement is true for hydrolysis or condensation.
Condensation Hydrolysis
Monomers are a product yes
Monomers are a substrate yes
Bonds are formed yes
Bonds are broken yes
Monomers are a product of hydrolysis, which breaks polymers apart. In this
process bonds are broken. In condensation, bonds are formed when monomers
are used as a substrate to form polymers.
47. Hydrolysis reactions are involved in ____ reactions.
a. transfer
b. anabolic
c. neutralization
d. combustion
e. catabolic
Hydrolysis reactions are catabolic reactions because they break bonds.
48. Hydrolysis involves…
a. water molecules as a substrate
b. polymers breaking apart
c. formation of polymers
d. a and b only
e. a, b and c are correct.
Hydrolysis involves water molecules used as a substrate to break apart polymers.
The result is the formation of monomers.
49. Which portion of this molecule represents a carboxylic acid?
A
B
C
D
Carboxylic acids (-COOH) can react in condensation.
Carbohydrates
50. Which of the following is a source of carbohydrates?
a. sugar, fruits, and bread
b. butter and oils
c. steaks
d. water
Sugar, fruits, and bread are sources of carbohydrates.
51. Answer the following questions about the structures and properties of
carbohydrates.
Question 1 / 3
Carbohydrates are not used for
a. cell recognition
b. energy storage
c. catalysis
d. cell walls
Question 2 / 3
Select all that apply. Carbohydrates contain _____ functional groups.
a. alcohols
b. ketones or aldehydes
c. amine
d. carboxylic acid
e. halogen
Question 3 / 3
When formed into long chain polymers, they can store energy for future use in
the cell such as starch in plants, and glycogen in humans. In plant cells,
carbohydrate polymers called cellulose
form rigid protective structures called the cell wall.
Cellulose, starch, glycogen
Question 1 Feedback
Carbohydrates are not used for catalysis, but are used for energy, energy storage,
structures like cell walls, and cell recognition like blood types.
Question 2 Feedback
Carbohydrates contain alcohols and either a ketone or aldehyde group.
Question 3 Feedback
When formed into long chain polymers, they can store energy for future use in
the cell such as starch in plants, and glycogen in humans. In plant cells,
carbohydrate polymers called cellulose form rigid protective structures called the
cell wall.
52. Classify the molecules as aldoses or ketoses:
Glucose Fructose Galactose
aldose
ketose aldose
ketose
aldose
ketose
Aldoses contain an aldehyde functional group on the top carbon; ketoses will
contain a ketone functional group on a middle carbon. Glucose and Galactose are
aldoses, Fructose is a ketose.
53. Select all that apply. Monosaccharides include
a. sucrose
b. lactose
c. glucose
d. fructose
e. cellulose
Monosaccharides include glucose, fructose, and galactose.
54. Click and drag to arrange the following by number of monomers, from
smallest number of monomers on the top to largest number on the bottom.
a. maltose
b. glycogen
c. glucose
glucose
maltose
glycogen
Glucose is a single monomer, maltose is a dimer that contains two monomers,
and glycogen contains many monomers.
55. Drag the terms to the correct location to complete the following sentences.
The main component of table sugar is sucrose, made of one molecule of glucose
which forms a six-member ring in nature, and one molecule of fructose also
known as fruit sugar.
The disaccharide found in milk is lactose, made of the monosaccharide galactose
that is also known as brain sugar and glucose which is the prominent
monosaccharide for energy.
The disaccharide maltose is made of two molecules of glucose.
Fructose, lactose, sucrose, galactose, maltose
The main component of table sugar is SUCROSE made of one molecule of
glucose which forms a six-member ring in nature, and one molecule of
FRUCTOSE also known as fruit sugar.
The disaccharide found in milk is LACTOSE, made of the monosaccharide
GALACTOSE that is also known as brain sugar and glucose which is the
prominent monosaccharide for energy.
The disaccharide MALTOSE is made of two molecules of glucose.
56. Glycosidc Bond
Click the glycosidic bond in the following disaccharide.
The glycosidic bond joins the two monomers, and forms an ether functional group.
57. For each disaccharide, chose the monomer(s) that are joined in the
disaccharide.
Fructose Galactose Glucose
Lactose yes yes
Sucrose yes yes
Maltose yes
Lactose is made of the monomers galactose and glucose. Sucrose is made of the
monomers fructose and glucose. Maltose is made of two glucose monomers.
58. Select all that apply. Carbohydrates can contain _____ functional groups.
a. alcohols
b. glycosidic
c. aldehydes
d. ketones
e. alkene
Carbohydrates can contain alcohol, and either ketone or aldehyde groups.
59. Where will you find sucrose?
a. storage of energy in plant cells
b. plant cell walls
c. storage of energy in animal cells
d. table sugar
Sucrose is found in table sugar.
60. Select the correct letter corresponding to the circled glycosidic bond in the
structure.
The glycosidic bond is the ether bond linking the two monomers.
61. Which monomers are used to form maltose?
a. fructose
b. glycogen
c. glucose
d. lactose
e. galactose
Two molecules of glucose are used to form the disaccharide maltose.
62. Select all that apply. Carbohydrates can be used for which of the following
cellular functions:
a. information storage
b. cell recognition
c. used for energy
d. energy storage
e. cell walls
Carbohydrates are used for cell recognition such as ABO blood groups, energy
storage such as glycogen, used as energy such as glucose, and cell walls such as
polysaccharides. They would not be used for information storage.
63. Determine if the molecule is a monosaccharide, disaccharide, or
polysaccharide.
Monosaccharide Disaccharide Polysaccharide
Lactose yes
Fructose yes
Cellulose yes
Sucrose yes
Fructose is a monomer, lactose and sucrose are disaccharides, and cellulose is a
polysaccharide. [Show Less]