Transcript Advanced Chemistry

Advanced Chemistry
Bell Ringers
Bell Ringer
• Pick Up Your Copy of the Syllabus and briefly
scan it. You will need to be ready to discuss 3
Questions OR Comments you have written
down. At this time your Bell Ringer will be
written on scratch paper or in the margin of
your syllabus. You will not be turning them in
for a grade but are expected to share our 3
items as part of class discussion.
Describe the classification of matter for
water and for oxygen. You might find the
image above helpful as well as the flow
diagram on page 11 of your book.
Significant Digits/Figures Video
• https://www.youtube.com/watch?v=6oj4y0d4
4nQ
a.
A.
B.
C.
D.
A chemical change
Cannot determine without
additional information
Neither a physical nor a
chemical change
A physical change
b.
A. A chemical change
B. Cannot determine without additional
information
C. Neither a physical nor a chemical
change
D. A physical change
c.
A.
B.
C.
D.
A chemical change
Cannot determine without additional
information
Neither a physical nor a chemical
change
A physical change
Sample Exercise 1.3 Converting Units of Temperature
A weather forecaster predicts the temperature will reach 31 °C. What is this temperature (a) in K, (b) in °F?
Solution
(a)
Using Equation 1.1, we have K = 31 + 273 = 304 K.
(b)
Using Equation 1.2, we have
Practice Exercise
Ethylene glycol, the major ingredient in antifreeze, freezes at -11.5 °C. What is the freezing point in (a) K,
(b) °F?
Solve the Practice Exercises
You might reference the examples in the Solution Portion above.
How would the darts be positioned on the target
for the case of “good accuracy, poor precision”?
A.
B.
C.
D.
Scattered closely and average position is away from center.
Scattered widely and average position is at the center.
Scattered closely and average position is at the center.
Scattered widely and average position is away from the center.
You will be solving the Practice Problem on the following slide. You have 3 minutes
to copy this problem into your learning log for reference before we do our bell
ringer practice problem.
Sample Exercise 1.12 Conversions Involving Density
What is the mass in grams of 1.00 gal of water? The density of water is 1.00 g/mL.
Solution
Before we begin solving this exercise, we note the following:
1.
We are given 1.00 gal of water (the known, or given, quantity) and asked to calculate its mass in
grams (the unknown).
2.
We have the following conversion factors either given, commonly known, or available on the back
inside cover of the text:
The first of these conversion factors must be used as written (with grams in the numerator) to give the
desired result, whereas the last conversion factor must be inverted in order to cancel gallons:
The unit of our final answer is appropriate, and we’ve taken care of our significant figures. We can further
check our calculation by estimating. We can round 1.057 off to 1. Then focusing on the numbers that do not
equal 1 gives 4 × 1000 = 4000 g, in agreement with the detailed calculation.
Sample Exercise 1.12 Conversions Involving Density
Continued
Solution
You should also use common sense to assess the reasonableness of your answer. In this case we know that most
people can lift a gallon of milk with one hand, although it would be tiring to carry it around all day. Milk is
mostly water and will have a density not too different from that of water. Therefore, we might estimate that a
gallon of water has mass that is more than 5 lb but less than 50 lb. The mass we have calculated, 3.78 kg ×
2.2 lb/kg = 8.3 lb, is thus reasonable as an order-of-magnitude estimate.
Practice Exercise
The density of benzene is 0.879 g/mL. Calculate the mass in grams of 1.00 qt of benzene.
Answer: 832 g
Below you have a Sample Problem and then a Practice
Problem to solve for your Bell Ringer. Feel free to write the
sample problem in your learning log as well.
Sample Exercise 1.5 Relating Significant Figures to the Uncertainty
of a Measurement
What difference exists between the measured values 4.0 g and 4.00 g?
Solution
The value 4.0 has two significant figures, whereas 4.00 has three. This difference implies that the 4.0 has
more uncertainty. A mass reported as 4.0 g indicates that the uncertainty is in the first decimal place. Thus,
the mass might be anything between 3.9 and 4.1 g, which we can represent as 4.0 ± 0.1 g. A mass reported
as 4.00 g indicates that the uncertainty is in the second decimal place. Thus, the mass might be anything
between 3.99 and 4.01 g, which we can represent as 4.00 ± 0.01 g. (Without further information, we cannot
be sure whether the difference in uncertainties of the two measurements reflects the precision or the
accuracy of the measurement.)
Practice Exercise
A sample that has a mass of about 25 g is placed on a balance that has a precision of ± 0.001 g. How many
significant figures should be reported for this measurement?
Bell Ringer
List 3 advantages and 3 disadvantages to True or
False questioning…
Chapter 1 Quiz
• Chapter 1 Learning Logs are due…Place in the
basket for grading
• Pick up your remotes and have out scratch
paper/calculators if you feel you need them
Bell Ringer….Substitute Here. Did not
use this Slide
Alpha particles are
Positively charged.
Analyze the image at
The right…
What can you infer about the nucleus from the
angles of interaction between an atom and an alpha
particle?
Bell Ringer
Carbon on the Periodic Table shows it has a
mass of 12.011, but there is no such thing as a
.011 of an atom.
Explain how the average atomic masses (atomic
weight) are found and how is that similar to
finding your average test score in this class if you
scored an 88%, 97%, 100% and 72%?
Bell Ringer
Complete the chart below:
Element
# Protons
Ca
20
# Neutrons
# Electrons
Mass #
40
Li
4
N
7
C-14
7
7
14
Cl-1
18
Al+3
14
Bell Ringer
Butane is a four carbon hydrocarbon chain.
Hydrocarbon means hydrogens and carbons.
The ending –ane means only single bonds. Draw
the structure for butane (Remember: Carbons
like to form 4 bonds each).
What is its molecular formula?
What is its empirical formula?
Bell Ringer
Copy the flow chart below into your Bell Ringer Notes.
Then write out the name for CaCl2.
Experiment 2 Lab Day 1 of 3
Pick up the Lab Manuel at the front of the room.
Open to page 29. Have your LAB Book out and
begin your log entry for the Table of Contents.
Name
Period #
Advanced Chemistry
Lab Book
Page Content
1 Table of Contents
2-5 Experiment 1
6- Experiment 2
1
Lab Day 2 of 3 Data Collection
Before you can begin collecting data…you must
have your lab book entry preapproved.
I. Procedures-short and sweet but shouldn’t
need the manual to know how to do the lab.
II. Safety section for chemicals and equipment
we are using.
III. Data/Observations (begin after approval)
Lab Day 3 of 3
We are in the library computer lab…
Remember a full lab report includes: Intro, Procedures,
Safety, Data & Observations, Calculations & Results (excel
graphs etc), Discussion of Results, References in ACS and
Additional Questions.
For this lab: Please submit typed Intro, Discussion of
Results and Additional Questions to our turnitin.com
account.
No 3rd Person! Individual work!
Bell Ringer
You have 3 minutes to list as many patterns that
exist on the periodic table that you
remember from the past.
What does the period # mean? What does the
group number mean? Atomic size? Atomic
Charge? Number of protons or electrons?
Bell Ringer
Pick up your chapter 2 study guide…
Use a Green highlighter to mark any concepts
you feel you know well.
Use a Pink highlighter to mark any concepts you
feel you need to study more before the exam.
Bell Ringer
What is the molecular formula for pentane, the
alkane with five carbons?
What is the name and molecular formula for the
alcohol derived from pentane?
Bell Ringer
Copy and Complete the Chart Below into your
Learning Log. Feel free to use Section 3.5 for
reference if needed.
Term
What Particle Changes?
Elemental Transmutation
Electron
Isotope
Electron is Lost
Anion
Bell Ringer
Draw a symbol to represent Single
Displacement, Double Displacement, Synthesis,
Decomposition and Combustion Reactions.
Please remember that symbols do not generally
contain numbers or letters.
Bell Ringer
Write a balanced equation for the following
problems…
Zinc and lead (II) nitrate react to form zinc
nitrate and lead.
Aluminum and hydrochloric acid react to form
aluminum chloride and hydrogen gas.
Bell Ringer
Convert 0.200 moles of H2S to molecules and
grams of sulfuric acid.
Bell Ringer
Write a paragraph that describes step by step
how to convert number of grams into
number of atoms.
Please remember the components of a good
WAC paragraph…Organization, Content,
Grammar and Critical Thinking.
Bell Ringer
Honors Chem Flash Back…Don’t use the book
unless you are absolutely stuck!
Ascorbic Acid (Vitamin C) contains 40.92% C,
4.58% H and 54.50% O by mass. What is the
empirical formula for ascorbic acid?
Bell Ringer
Honors Chem Flash Back…Don’t use the book
unless you are absolutely stuck!
Determine how many grams of water are
produced in the oxidation of
1.00 g of glucose, C6H12O6.
Bell Ringer
Your Learning Log is Due October 23rd (Thursday).
You should have Chapter 3 completed.
You have this class period to update any entries but
BEFORE we do that…Flip back through your Log and
find one question you have about the last 3
chapters. EVERYONE will share ONE question.
Note: It doesn’t have to be a book question. It can
be a general question about what we have learned.
Bell Ringer
Day 1 of 3 for Experiment 3
Get your lab manual from the cabinet and begin
writing up our Lab Log entry.
I. Procedures…detailed by simplified
II. Safety-MSDS is a good resource
III. Data/Observation Table ready for collection
IN PEN…Partners are fine to this point
Lab Day 2 of 3 Data Collection
Before you can begin collecting data…you must
have your lab book entry preapproved.
I. Procedures-short and sweet but shouldn’t
need the manual to know how to do the lab.
II. Safety section for chemicals and equipment
we are using. MSDS is your BFF.
III. Data/Observations (begin after approval)
Lab Day 3 of 4
We are in the library computer lab
FOR SURE TOMORROW!!!
Remember a full lab report includes: Intro, Procedures,
Safety, Data & Observations, Calculations & Results (excel
graphs etc), Discussion of Results, References in ACS and
Additional Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Lab Day 4 of 4
In the computer lab…
Remember a full lab report includes: Intro, Procedures,
Safety, Data & Observations, Calculations & Results (excel
graphs etc), Discussion of Results, References in ACS and
Additional Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Bell Ringer
Solve the following nuclear reaction for the
unknowns: A, Z and X
238
U
92

14
4
+
A
C
6
A
X
Z

0
X
Z
He
2
+
e
-1
Bell Ringer
Take out your phones or use school equipment
to find Socrative…Follow the directions below to
get logged into our Chapters 1-3 Review.
Chapters 1-3 Exam
Pick up your remote from the CPS bag. Be sure
that it is YOUR number. Begin testing
immediately.
You may use: Scratch paper and a NONProgrammable Calculator. No Cell Phones!
GoodLuck#BigDay#StudyingIsGoodForU
Bell Ringer
Solubility Mnemonics
http://www.youtube.com/watch?v=AsCLuLS-yZY
Make your entry for 10/29/14 and be ready to
copy the mnemonic for Solubility as your entry.
We will be using this so take GOOD NOTES…
Bell Ringer
Classify CaCl2, HNO3, C2H5OH, HCOOH, and
KOH as a strong, weak or electrolyte…
Bell Ringer
Classify CaCl2, HNO3, C2H5OH, HCOOH, and KOH as a
strong electrolyte, weak electrolyte or nonelectrolyte…
All ionic compounds are strong electrolytes (see table 4.3)
so they are strong. HNO3 is an acid therefore we classify it
as strong (see table 4.2). HCOOH is a weak acid so it is a
weak electrolyte. C2H5OH is not an acid or base so it is a
nonelectrolyte.
Bell Ringer
If we have Pb(NO3)2, which of the following
metals will be oxidized? You will need to refer to
table 4.5 for Activity Series.
Zn
Cu
Fe
Bell Ringer
A reaction can occur with a metal if it is located above the
reactant that is the meatal in its oxidized form. (see table 4.5).
Zn-Yes
Cu-No
Fe-Yes
Bell Ringer
How many grams of Na2SO4 are required to
make 0.350 L of 0.500 M Na2SO4?
Sample Exercise 4.13 Using Molarity to Calculate Grams of Solute
How many grams of Na2SO4 are required to make 0.350 L of 0.500 M Na2SO4?
Solution
Analyze We are given the volume of the solution (0.350 L), its concentration (0.500 M), and the identity of the solute
Na2SO4 and asked to calculate the number of grams of the solute in the solution.
Plan We can use the definition of molarity (Equation 4.32) to determine the number of moles of solute, and then
convert moles to grams using the molar mass of the solute.
Solve Calculating the moles of Na2SO4 using the molarity and volume of solution gives
Sample Exercise 4.13 Using Molarity to Calculate Grams of Solute
Continued
Because each mole of Na2SO4 has a mass of 142 g, the required number of grams of Na2SO4 is
Check The magnitude of the answer, the units, and the number of significant figures are all appropriate.
Practice Exercise
(a) How many grams of Na2SO4 are there in 15 mL of 0.50 M Na2SO4? (b) How many milliliters of 0.50 M
Na2SO4 solution are needed to provide 0.038 mol of this salt?
Answer: (a) 1.1 g, (b) 76 mL
Bell Ringer
FROM MEMORY
What is our mnemonic for the
8 Solubility Rules?
OR
List the 8 Solubility Rules.
Bell Ringer
What is our mnemonic for the
8 Solubility Rules?
PMS *
Nitrates NO3Pb2+
Acetates C2H3O2Mercury Hg22+
Group 1
Silver Ag+
@*Sulfates SO42Ammonium NH4+
*Group 17
Castro Bear @
Ca2+
Sr2+
Ba2+
Bell Ringer
Day 1 of 3 for Group IA & Group IIA Cation Lab
You will use a hand out to begin writing up our
Lab Log entry.
I. Procedures…detailed by simplified (should have
prediction prior to starting)
II. Safety-MSDS is a good resource
III. Data/Observation Table ready for collection
IN PEN…Partners are fine to this point
Lab Day 2 of 5 Data Collection
Before you can begin collecting data…you must
have your lab book entry preapproved.
I. Procedures-short and sweet but shouldn’t
need the manual to know how to do the lab.
WITH A Prediction!
II. Safety section for chemicals and equipment
we are using. MSDS is your BFF.
III. Data/Observations (begin after approval)
Lab Day 3 of 5
We are in the library computer lab
Remember a full lab report includes: Intro, Procedures,
Safety, Data & Observations, Calculations & Results (excel
graphs etc), Discussion of Results, References in ACS and
Additional Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Lab Day 4 of 5
Unknown Identification Day!
We are in the library computer lab tomorrow…
Remember a full lab report includes: Intro, Procedures, Safety,
Data & Observations, Calculations & Results (excel graphs etc),
Discussion of Results, References in ACS and Additional
Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Lab Day 5 of 5
We are in the library computer lab
Remember a full lab report includes: Intro, Procedures,
Safety, Data & Observations, Calculations & Results (excel
graphs etc), Discussion of Results, References in ACS and
Additional Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Bell Ringer
Chapter 4 Quiz Today…
Please have your remotes, scratch paper if you
choose, Periodic Table and calculator ready!
Bell Ringer
Considering the formula for work…
W=fxd
And considering the formula for Force…
F=mxa
We use the unit Joule or J for energy. What is a J
equal to if not using its short hand?
Bell Ringer
If I told you in an experiment that a gas was
compressed 910 kJ/mol (the work) and the heat
gained was -680 kJ/mol, what would the change
in E be?
Hint: E = q + w
Bell Ringer
w = -PV for a gas at STP
H = E +PV
H = (E +PV)
H = E +PV assume P is constant
Remember E = q + w and work associated with
compressing a gas is w = -PV
H = (q + w) - w
p
Bell Ringer
What to the roots mean for the following
words?
Exothermic
Endothermic
Bell Ringer
What to the roots mean for the following
words?
Exothermic - “to leave or outer” & “heat”
Endothermic- “to enter or interior” & “heat”
Bell Ringer
How much heat is released when 4.50 g of
methane gas is burned
in a constant-pressure system?
(Use the information given in Equation 5.18.)
Bell Ringer
Our
goal
is
to
use
a
thermochemical
equation
to
calculate
thegas
heat
produced
when
a specific
amount
of
methane
is
combusted.
According
to
Equation
5.18,
890
kJ
is
released
by
the
system
when 1 mol CH is burned at constant pressure.
4
Equation
5.18
provides
us
with
a
stoichiometric
conversion
factor:
(1mol
CH
=
890
kJ).
Thus,
we
4
can
convert
moles
of CH4 to
kJ ofofenergy.
First,
however,
we
must
convert
grams
CH
to
moles
of
4
CH
the conversion
is grams
CH4
4. Thus,
(given)
→ moles
CH4 → kJsequence
(unknown
to be found).
By
adding
the
atomic
weights
of
C
and
4
H,
we
have
1 mol CH
CH4. We
can
use the
4 = 16.0 factors
appropriate
conversion
to
convert
grams
of
CH4 to moles of CH4 to kilojoules:
The
negative
sign
indicates
that
the
system
released
250 kJ into the surroundings.
Bell Ringer
The enthalpy of reaction for the combustion of C
to CO2 is –393.5 kJ/mol C, and the enthalpy for
the combustion of CO to CO2 is –283.0 kJ/mol C:
Using these data, calculate the enthalpy for the
combustion of C to CO:
Bell Ringer Solution
Bell Ringer
Day 1 of 3 for Group IIIA & Group IVA & VA Cation Lab
You will use a hand out to begin writing up our
Lab Log entry.
I.
Procedures…detailed by simplified (should have
prediction prior to starting)
II. Safety-MSDS is a good resource
III. Data/Observation Table ready for collection
IN PEN…Partners are fine to this point
Lab Day 2 of 4 Data Collection
Before you can begin collecting data…you must
have your lab book entry preapproved.
I. Procedures-short and sweet but shouldn’t
need the manual to know how to do the lab.
WITH A Prediction!
II. Safety section for chemicals and equipment
we are using. MSDS is your BFF.
III. Data/Observations (begin after approval)
Lab Day 3 of 4
We are in the library computer lab
Remember a full lab report includes: Intro, Procedures,
Safety, Data & Observations, Calculations & Results (excel
graphs etc), Discussion of Results, References in ACS and
Additional Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Bell Ringer
The standard enthalpy change for the reaction
CaCO3(s)
CaO(s) + CO2(g) is 178.1 kJ.
Use Table 5.3 to calculate the standard enthalpy
of formation of CaCO3(s).
Don’t Take Too LONG!
Quiz Today over Chapter 5!
Bell Ringer Solution
Chapters 3-5 Exam
Pick up your remote from the CPS bag. Be sure
that it is YOUR number. Begin testing
immediately.
You may use: Scratch paper and a NONProgrammable Calculator. No Cell Phones!
Bell Ringer
A light emits a light with a wave length 580 nm.
What is the frequency (Hint for some of you that
need it c = f x w…you know who you are).
P.S. Another hint for those that need it…convert
nm to meters.
Bell Ringer
Write a paragraph that describing the steps
you would use in order to solve the
following problem:
Calculate the energy of one photon of yellow
light that has a wavelength of 589 nm.
Bell Ringer
Analyze Our task is to calculate the energy, E, of a photon, given λ = 589 nm.
Plan We can use Equation 6.1 to convert the wavelength to frequency: v = c/λ
We can then use Equation 6.3 to calculate energy: E = hv
Solve The frequency, v, is calculated from the given wavelength, as shown
in Sample Exercise 6.2: v = c/λ = 5.09 × 1014s-1
The value of Planck’s constant, h, is given both in the text and in the table of physical
constants on the inside back cover of the text, and so we can easily calculate E:
E = (6.626 × 10-34 J-s)(5.09 × 1014 s-1) = 3.37 × 10-19 J
Comment If one photon of radiant energy supplies 3.37 ×10-19 J, then one mole of
these photons will supply
(6.02 × 1023 photons/mol)(3.37 × 10-19J/photon) = 2.03 × 105J/mol
Bell Ringer
What is the wavelength of an electron moving with a
speed of 5.97 × 106 m/s?
The mass of the electron is 9.11 × 10-31 kg.
Bell Ringer
Analyze We are given the mass, m, and velocity, v, of the electron, and we must
calculate its de Broglie wavelength, λ.
Plan The wavelength of a moving particle is given by Equation 6.8, so λ is
calculated by inserting the known quantities h, m, and v. In doing so, however,
we must pay attention to units.
Solve Using the value of Planck’s constant, h = 6.626 × 10-34 J-s
We have the following:  = h/(m)
 = h/(m)
 =
(6.626 x 10-34 js)
x (1kgm2/s2)
(9.11 x 10-31 kg) (5.97 x 106 m/s)
1J
Comment By comparing this value with the wavelengths of electromagnetic
radiation shown in Figure 6.4, we see that the wavelength of this electron is
about the same as that of X-rays.
Bell Ringer
Without referring to Table 6.2, a) predict the
number of subshells in the fourth shell, that is, for n
= 4. (b) Give the label for each of these subshells.
(c) How many orbitals are in each of these
subshells?
Hint: We are given the value of the principal
quantum number, n. We need to determine the
allowed values of l and ml for this given value of n
and then count the number of
orbitals in each subshell.
Bell Ringer
There are four subshells in the fourth shell, corresponding to the four
possible values of l (0, 1, 2, and 3).
These subshells are labeled 4s, 4p, 4d, and 4f. The number given in the
designation of a subshell is the principal quantum number, n; the letter
designates the value of the angular momentum quantum number, l :
for l = 0, s; for l = 1,p; for l = 2,d; for l = 3,f.
There is one 4s orbital (when l = 0, there is only one possible value of
ml: 0). There are three 4p orbitals (when l = 1, there are three possible
values of ml: 1, 0, -1). There are five 4d orbitals (when 1 = 2 , there are
five allowed values of ml: 2, 1, 0, -1, -2). There are seven 4f orbitals
(when l = 3, there are seven permitted values of ml: 3, 2, 1, 0, -1, -2, 3).
Bell Ringer
A student claims Phosphorus, element 15 has
the electrons configuration 1s22s22p63s23p2. Are
the correct or false? Justify your answer.
How many unpaired electrons does a
phosphorus atom possess?
Bell Ringer
Answers: (a) 1s22s22p63s23p3, (b) three
Bell Ringer
Mendeleev (& arguably Meyer) and Mosely both
influenced the development of the modern
Periodic Table. Who do you think is more
responsible for what we use and why?
Bell Ringer
Rank the following ions in order of increasing
size (smallest to biggest).
ClCa2+
S2K+
Bell Ringer
Rank the following ions in order of increasing
size (smallest to biggest).
Ca2+
K+
Cl-
S2-
Bell Ringer
Silicon has the electron configuration
1s22s22p63s23p2
Is the following statement T/F and WHY?
“The 2p electrons will be easier to remove then
the 3p electrons because they are lower in
energy level.”
Bell Ringer
The electron affinity for Cl is -349 and -60 for
Lithium. What is the relationship between
ionization energy and the electron affinity?
Don’t take forever because you are going to cut
into your quiz time…
Chapters 6 & 7 Exam
Pick up your remote from the CPS bag. Be sure
that it is YOUR number. Begin testing
immediately.
You may use: Scratch paper and a NONProgrammable Calculator. No Cell Phones!
Bell Ringer
Consider the lattice energies on page 293. What
relationship is there between electronegativity
and the lattice energy required
to break the bonds?
Bell Ringer
Draw the Lewis Dot structures for CO2 and NH3.
Identify which one is a polar molecule and
justify your answer. Page 299 has the
electronegativity chart if you need assistance.
Bell Ringer
Draw the Lewis Dot Structure for NO3-. What is a
resonance structure and how does it impact
your drawing?
Using data from Table 8.4, estimate H for the reaction
Hint: We are asked to estimate the enthalpy
change for a chemical reaction by using
average bond enthalpies for the bonds broken
and formed.
In the reactants, we must break twelve C—H
bonds and two C—C bonds in the two
molecules of C2H6 and seven O2 bonds in the
seven O2 molecules. In the products, we form
eight C==O bonds (two in each CO2) and
twelve O—H bonds (two in each H2O).
Using Equation 8.12 and data from Table 8.4, we have
H = [12D(C—H) + 2D(C—C) + 7D(O2)] – [8D(C==O) + 12D(O—H)]
= [12(413 kJ) + 2(348 kJ) + 7(495 kJ)] – [8(799 kJ) + 12(463 kJ)]
= 9117 kJ – 11948 k J
= –2831 kJ
This estimate can be compared with the value of
–2856 kJ calculated from more accurate thermochemical
data meaning the estimate is reasonable.
Bell Ringer
A single bond is usually longer than a double
and a double bond usually has a longer bond
length then a triple.
What relationship would there be between
single, double and triple bonds & the bond
enthalpy associated with breaking those bonds?
Bell Ringer
What do you have to know to determine a bond
angle. Think geometry…You can’t have an angle
if you don’t have __________.
Bell Ringer
Draw the the molecular geometry for COCl2. Use
this image to estimate the bond angles between
the C-0 and the C-Cl bonds.
Bell Ringer
Justify if you agree or disagree with the
following statement: “SnCl3 is a polar molecule.”
Hint: Draw the molecular geometry and then
use the electronegativities to determine if it has
polarity.
Bell Ringer
Justify if you agree or disagree with the
following statement: “SnCl3 is a polar molecule.”
Bell Ringer
Justify if you agree or disagree with the
following statement: “SnCl3 is a polar molecule.”
Bell Ringer
Indicate the orbital hybridization around
the central atom in NH2–.
HINT: To determine the central atom hybrid orbitals,
we must know the electron-domain geometry around the
atom. Thus, we draw the Lewis structure to determine
the number of electron domains around the central
atom. The hybridization conforms to the number and
geometry of electron domains around the central atom
as predicted by the VSEPR model.
Because there are four electron domains around N, the electron-domain
geometry is tetrahedral. The hybridization that gives a tetrahedral electrondomain geometry is sp3 (Table 9.4). Two of the sp3 hybrid orbitals contain
nonbonding pairs of electrons, and the other two are used to make bonds with
the hydrogen atoms.
Bell Ringer
Why is it important that the sp2 hybrid orbitals of
the two carbon atoms lie in the same plane?
A. To ensure that a sp2 hybrid orbital on one carbon atom can bond to
a sp2 hybrid orbital on the other carbon atom or a hydrogen atom.
B. To ensure that the H—C—H bond angle is 120°.
C. To ensure that the unhybridized p orbitals on the carbon atoms are
aligned properly to form a pi bond.
D. To ensure that the H—C—C bond angle is 120°.
Bell Ringer
Formaldehyde has the Lewis structure
Describe how the bonds in formaldehyde are formed in terms of overlaps of hybrid and unhybridized oribitals.
Hint: Single bonds σ are bonds,
and double bonds consist of
one π bond and one π bond.
The ways in which these bonds
form can be deduced from the
molecular geometry, which we
predict using the VSEPR model.
The C atom has three electron domains around it, which suggests a trigonal-planar
geometry with bond angles of about 120°. This geometry implies sp2 hybrid orbitals
on C (Table 9.4). These hybrids are used to make the two C — H and one C — O
bonds to C. There remains an unhybridized 2p orbital on carbon, perpendicular to the
plane of the three sp2 hybrids.
The O atom also has three electron domains around it, and so we assume it has
sp2 hybridization as well. One of these hybrid orbitals participates in the C —
O σ bond, while the other two hold the two nonbonding electron pairs of the
O atom. Like the C atom, therefore, the O atom has an unhybridized 2p orbital
that is perpendicular to the plane of the molecule. These two orbitals overlap to
form a C — O π bond (Figure 9.25)
Chapters 8 & 9 Exam
Pick up your remote from the CPS bag. Be sure
that it is YOUR number. Begin testing
immediately.
You may use: Scratch paper and a NONProgrammable Calculator. No Cell Phones!
Bell Ringer
Day 1 of 4 for our Third Cation Lab
You will use a hand out to begin writing up our
Lab Log entry.
I. Procedures…detailed by simplified (should have
prediction prior to starting)
II. Safety-MSDS is a good resource
III. Data/Observation Table ready for collection
IN PEN…Partners are fine to this point
Lab Day 2 of 4 Data Collection
Before you can begin collecting data…you must
have your lab book entry preapproved.
I. Procedures-short and sweet but shouldn’t
need the manual to know how to do the lab.
WITH A Prediction!
II. Safety section for chemicals and equipment
we are using. MSDS is your BFF.
III. Data/Observations (begin after approval)
Lab Day 3 of 4
Unknown Day!
May the force be with you and not the m x a kind…
We are in the library computer lab TOMORROW!
Remember a full lab report includes: Intro, Procedures, Safety,
Data & Observations, Calculations & Results (excel graphs etc),
Discussion of Results, References in ACS and Additional
Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Lab Day 4 of 4
We are in the library computer lab
Remember a full lab report includes: Intro, Procedures, Safety,
Data & Observations, Calculations & Results (excel graphs etc),
Discussion of Results, References in ACS and Additional
Questions.
You will be submitting all 8 sections to the turnitin.com
account.
No 3rd Person! Individual work!
Bell Ringer
ACS Practice for the Final Day…No time to play.
Be seated and ready for instructions.
Today’s Topic:
Atomic Structure
Bell Ringer
ACS Practice for the Final Day…No time to play.
Be seated and ready for instructions.
Today’s Topic:
Molecular Structure and Bonding
Bell Ringer
ACS Practice for the Final Day…No time to play.
Be seated and ready for instructions.
Today’s Topic:
Stoichiometry
Bell Ringer
ACS Practice for the Final Day…No time to play.
Be seated and ready for instructions.
Today’s Topic:
States of Matter and Solutions
Bell Ringer
ACS Practice for the Final Day…No time to play.
Be seated and ready for instructions.
Today’s Topic:
Energetics
Finals Bell Ringer
Pick up your remote, take out your calculator
(no cell phones) & scratch paper.
No personal periodic tables but the one in our
test booklet or on the wall is fair game.
Your grade is based on number correct so it is to
your best interest to answer every question.