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BITS Pilani
Pilani Campus
Welcome
CHEM F111 : General Chemistry
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BITS Pilani, Pilani Campus
General Chemistry (Overview of handout)
(2016-17: Ist Semester)
(22 Lectures)
(12 Lectures)
• Quantum theory
• Conformation
• Atomic structure and spectra • Stereochemistry
• Spectroscopy:
• Types of reactions:
• Rotational & Raman
• Vibrational
• NMR
• Elimination
• Addition
• Substitution
• Pericyclic
• Chemical thermodynamics
• Aromatic compounds
• Chemical Kinetics
• Coordination compounds (6 Lectures)
• Octahedral, Tetrahedral , Square planar geometries
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Books
Text Books
T1: P.W. Atkins and Julio de Paula, Elements of Physical Chemistry: 6th
Edition, Oxford University Press, Oxford, reprinted in 2015.
T2: T. W. Graham Solomons and Craig B. Fryhle, Organic Chemistry,
10th Edition, John Wiley & Sons, Inc. New York, 2011
Reference Books:
R1: Physical Chemistry, David Ball
R2: J. D. Lee, Concise Inorganic Chemistry, 5th Edition, Blackwell
Science, Oxford, 1999.
R3: Inorganic Chemistry: Principles of Structure and Reactivity, 4th
Edition, Huheey, Keiter
R4: R. T. Morrison and R. Boyd, ‘Organic Chemistry’, 6th Edition, PHI,
New Delhi, 1992.
BITS Pilani, Pilani Campus
General Chemistry (Evaluation components)
Component Duration Weightage Date and Time
%
[Marks]
Mid- Sem.
90 min.
30
As per the time
Exam.
[90 M]
table
Continuous
Evaluation‡
15 min.
(each)
30
[90 M]
Compre.
Exam.
3 hours
40
[120 M]
Continuous
Remarks
Closed book
(i) Assignment
(Open book)
(ii) Quiz
(Closed book)
10-December- (i) 20% Closed Book
2016, AN
:MCQ
(ii) 20% Open Book:
Descriptive
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Continuous Evaluation: 30% [90 Marks]
Tutorial Hour: Clarification of doubts, further discussion and
interactions , problem solving, periodical and continuous evaluation
(i) Assignments (Open Book):
-A set of problems will be assigned periodically (on Nalanda).
-Based on the concepts of the assigned problems, different questions
will be given for solving in the Assignment test.
-Three Assignments (15 Marks each) will be conducted. (Common time)
Tentative Dates: 31-August; 21-September; 9-November-2016 (5.00 PM)
(ii) Quiz (Closed Book):
-Short questions/numerical/short notes
-Four quizzes (15 Marks each) will be conducted in respective tut.
Best six (out of seven continuous evaluation components) will be
considered.
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Assignment/Lecture slides/Notices will be uploaded on
the Nalanda (upon activation).
Please register yourself on Nalanda
Until Nalanda is activated: Lecture slides can be
downloaded from Department of chemistry website:
http://www.bits-pilani.ac.in/pilani/pilaniChemistry/courserelated
Password: BITSPILANI
BITS Pilani, Pilani Campus
CLASSROOM RULES
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Quantum Theory: Background
Classical Physics:
Describes the motion of macroscopic objects,
from pendulum, projectiles to parts
of machinery, as well as astronomical objects,
such as spacecraft, planets, stars, and galaxies.
Newton Laws of motion (1687)
Newton Theory of gravity
Euler Law of motion
Galileo Contribution to astronomy
unaltered for three centuries till end of 19th Century
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Classical Mechanics: Consequences
1. Predict a precise trajectory for particles with precisely
specified locations and momenta at each instant.
2. Any kind of motion can be excited to any arbitrary value
of the energy
3. Waves and Particles are distinct concepts
Certain Phenomena were unexplainable ???
? Black body radiation
? Photoelectric effect
? Electron diffraction
? Line spectra of atoms
……….Foundation of Quantum Mechanics
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Black body
• Study of Interaction of light with matter was in progress.
(How light was emitted or absorbed ??)
• Any object radiates energy, when heated. The amount of
energy emitted, and its frequency distribution depends on
the temperature and on the material.
• Black Body: An opaque object that is a perfect
absorber and a perfect emitter.
- At room temperature, such an object
would appear to be perfectly black.
- If heated to a high temperature, it
will begin to glow with thermal radiation
Actual black bodies don't exist in nature
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Nearly-perfect
black body
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Black body radiation-the phenomena
 At constant T, Intensity increases as λ
increases, attains a maximum value and
then decreases.
 Not all the wavelengths of light are
emitted equally.
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Intensity (I) or
Power density
• Such solid black bodies, when heated to glowing emitted a
continuous spectrum composed of all wavelengths of light,
called Black Body/cavity/complete/thermal radiations.
• The distribution of absorbed or emitted radiation depends
on the absolute temperature, not on the body material.
?
Wavelength
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Wien’s Observation: 1893
Wilhelm Wien quantified the
relationship between blackbody
temperature and the wavelength of
the spectral peak.
• With increase in T, the λmax shifts
towards shorter wavelength.
λmax T = b
b = 2.9 mmK = 0.29 cmK
[Wien’s Displacement Law]
The wavelength of maximum emission from a blackbody is
inversely proportional to its temperature.
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Stefan-Boltzman Observations: 1884
The Stefan–Boltzmann law describes the power radiated
from a black body in terms of its temperature.
Area under the curve at T = Total Power per unit surface area (M)
M is proportional to 4th power of absolute temperature
M = σT4
(W/m2)
[Stefan-Boltzmann Law]
 = 5.6697 x 10-8 Wm-2K-4
Used to estimate the
temperature of Sun
The Sun at 5800K and a hot campfire at perhaps
800 K give off radiation at a rate proportional to
the 4th power of the temperature
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Blackbody Radiation: Explanation
I. Rayleigh-Jeans Explanation (1900-1905)
The Rayleigh-Jeans Radiation Law was a useful but not completely
successful attempt at establishing the functional form of the spectra
of thermal radiation through classical arguments.
This attempt was based on certain assumptions (believed to be
true at that time).
Assumptions:
 Black body cavity is made up of charged particles which
behaves as tiny oscillators by thermal accelerations and emit
radiations.
 Energy emitted by atomic oscillations could have any
continuous value.
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Rayleigh-Jeans Law
Energy density (d) is the energy per unit volume associated
with radiation of wavelength from λ to λ+dλ :
dE =  dλ = (8πkT/λ4) dλ
k =Boltzmann constant
 Energy density rises without
bound as λ decreases.
 Infinite energy density at short
wavelengths. (Infinite energy in
the system!
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Rayleigh-Jeans Law:
unsuccessful attempt to explain the black body radiation
spectrum.
Rayleigh-Jeans Equation predicts that
Oscillators of short wavelength (UV) are excited even
Real
at room temperature.: This cannot be true
Picture
This paradox:
ULTRAVIOLET CATASTROPHE!
 Quite Successful at long wavelengths.
Θ Rayleigh_Jeans Law predicts an Ultraviolet catastrophe that does not
occur in real.
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Blackbody Radiation: Explanation
II. Planck’s Explanation (1900-1905)
attempts to describe the emission spectrum from a black
body at a given temperature through Quantization
hypothesis.
Crucial Assumption:
• An oscillator of frequency ν cannot
be excited to any arbitrary energy, but
to only to integral multiples of a
fundamental unit or quantum of
energy hν; h = 6.626 x 10-34 Js, the
Planck constant.
ΔE=nhν
i.e. Energy of an oscillator is
quantized
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Planck Radiation Distribution Law
dE= d= (8π/λ4) dλ (hc/λ) [e(hc/λkT) -1]-1
Average
energy
c is speed of light, k is Boltzmann’s constant and h is Planck’s constant.
Planck proposed empirical formula
describe the curve of blackbody
radiation
exactly
for
all
wavelengths.
Planck expression reproduces the
experimental distribution with
h = 6.626 x 10 –34 Js
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Planck Law: Success story
 Planck's hypothesis: An oscillator cannot be excited unless it
receives an energy of at least hν (as this is the minimum amount
of energy an oscillator of frequency ν may possess above zero).
 For high frequency oscillators (large ν, low ), the amount of
energy hν is too large to be supplied by the thermal motion of the
atoms in the walls, and so they are not excited.
dE = (8πhc/λ5) dλ [e(hc/λkT) -1]-1
At small , ehc/kT 
(Exponential is large)
 faster than 5
Energy density 0 as   0
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UV Catastrophe
avoided
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The Magic of Planck’s formula
maxT = hc/5k (constant)
Wien’s Law
 = 2 π5k4/15h3c2)T4 = T4
Stefan Boltzman Law
Differentiate d/dλ = 0 for
calculating max (at low λ)
M = ( (λ, T) dλ
dE = dλ = (8π/λ4) (hc/λ) [e(hc/λkT) -1]-1 dλ
exp (hc/λkT) = 1 + hc/λkT +1/2(hc/λkT)2
For long wavelengths,
when hc/λ << kT
+ ……
Dropping
Rayleigh-Jeans formula
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