3.091 Fall Term 2009
T est #3
Monday, November 23, 2009 11:05 a.m. 11:55 a.m.
Name:
solution outlines Donald R. Sadoway
Recitation Instructor:
A complete test consists of 6 questions. Write your answers on these pages. State your assumptions and show calc
3.091 Fall Term 2007
H omework Quiz #9A
solution outlines
log10 (rate)
(a) Urbium (Ur) is an upscale element found in big cities. Its oxide (UrO2) is not very stable and
decomposes readily at temperatures exceeding 66C. The figure below shows how the rate
3.091 Fall Term 2007
H omework Quiz #8B
solution outlines
(a) A melt of silicate glass, g1, cooled at rate, r1, has glass transition temperature, Tg1. A new
glass, g2, is formulated by the addition of CaO to g1. If a melt of g2 is cooled at rate, r1, how
3.091 Fall Term 2007
H omework Quiz #8A
solution outlines
(a) On a plot of molar volume, Vm, versus temperature, T, sketch cooling curves for a borate melt that
solidifies to form crystalline B2O3; and amorphous B2O3. Indicate which material was cooled mo
3.091 Fall Term 2007
H omework Quiz #6A
solution outline
(a) (i) In the cubic unit cell below sketch (030).
(ii) In the cubic unit cell below sketch [030].
z
z
y
x
y
x
(b) You suspect that the silver you purchased on eBay is contaminated with a heavy meta
3.091 Fall Term 2007
H omework Quiz #5B
Solution outline
Answer the following questions about the tetrafluorobromate ion (BrF4+).
(1) draw the Lewis structure
(2) circle all bonding orbitals
(3) indicate the polarity of the Br F bond
(4) state whether the
3.091 Fall Term 2007
H omework Quiz #5A
Solution outline
Answer the following questions about the hydronium ion (H3O+).
(1) draw the Lewis structure
(2) circle all bonding orbitals
(3) indicate the polarity of the H O bond
(4) state whether the molecule i
3.091 Fall Term 2007
H omework Quiz #3B
solution outlines
(a) Calculate the de Broglie wavelength of an electron moving with the same energy as that of a
photon of wavelength, , equal to 3.091 nm (3.091 109 m).
begin by equating energies: E photon
and E p
3.091 Fall Term 2007
H omework Quiz #3A
solution outlines
(a) Calculate the de Broglie wavelength of a neutron moving with the same energy as that of a
photon of frequency, , equal to 3.091 1014 Hz.
begin by equating energies: E photon
and E photon
= h
an
name:_
3.091 Fall Term 2007
H omework Quiz #2B
September 18
Afternoon sections question.
(a) In a gas discharge tube what is the minimum frequency () of a photon capable of ionizing
ground-state electrons in He+?
here is the central concept: the energy of
name:_
3.091 Fall Term 2007
H omework Quiz #2A
September 18
Morning sections question.
(a) Show by means of a calculation that blue light of wavelength, = 444 nm, is capable of
exciting electrons in He+(g) from the state n = 3 to n = 4.
lets equate the en
3.091 Fall Term 2007
H omework Quiz #1B
solution outline
(a) Lithium has two isotopes, 6Li and 7Li. Which isotope has the higher natural abundance?
from the periodic table, you see that the atomic mass of Li is 6.941, which must be the
weighted sum of the
3.091 Fall Term 2007
H omework Quiz #1A
solution outline
(a) Copper has two isotopes, 63Cu and 65Cu. Which isotope has the higher natural
abundance?
from the periodic table, you see that the atomic mass of Cu is 63.546, which must be the
weighted sum of t
3.091 Fall Term 2007
H omework Quiz #9B
solution outlines
log10 (rate)
catalyzed
reaction
slope, n = 2
intercept, k = 3.091
log k = 0.49
log10 (concentration)
(a) The fictitious compound, pandemonium fluoride (Pn2F3), decomposes readily at temperatures
ex