Unformatted text preview: CHEM 200 Fall 2016 CHEM _______ Exam 2-B November 25, 2016 Lab Section Number: _____ Name (printed):___________________________________________
This exam consists of 36 questions all of equal value for a total of 225
points. Make sure that your test has all of the pages. Please read each
problem carefully. There are no intentionally misleading questions; each
problem should be taken at its face value. Please mark your answers on
the Scantron sheet provided to you and on the actual exam.
You will be given a periodic table and an exam information sheet to use
during the exam. You may remove it from the exam make it more
accessible. You may also use the designated Casio fx-300ms-plus
calculator or equivalent non-programmable non-graphing scientific
calculator during the exam. Use the back pages of the test as scratch paper.
You are not allowed to use any devices capable of accessing the internet,
textbooks, notes, or homemade reference sheets during the exam.
You may leave if you finish the exam early. Give the exam and the
information sheet to your TA and leave quietly without disturbing other
students. Before leaving, check that all your answers have been properly
entered on the Scantron sheet and the exam and that your name is written
on every page of the exam and on the Scantron sheet.
All cell phones and electronic devices must be turned off and put away.
Please remove all hats and caps. Place your books and all papers out of
sight under your seat. If the TA believes that you might be looking at your
neighbor’s paper, you will be asked to move to a new location.
Exam scores will be posted on Blackboard as soon as the grading is
complete. Your test will be returned to you in the first lab meeting of next
week. If you have any questions regarding the grading of your exam,
please notify your TA.
The time available for the exam is 120 minutes. Good luck! 1 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 Please mark your answers on the scantron sheet using a #2 pencil and also mark your
answers on the exam itself.
Mark the test form version “002” on your scantron.
1. Calculate heat when 28.6 g of water is heated from 22.0 °C to 78.3 °C. (a)
(e) 0.385 kJ
1.61 x 103 kJ 2. Which of the following frequencies of electromagnetic radiation has the shortest
(e) 1 kHz
1 MHz 3. The AM station KBOR plays your favorite music from the 80's and 90's at 1290 kHz. Find
the wavelength of these waves. (a)
(e) 4.30 x 10-2 m
2.32 nm 4. A radio wave has a frequency of 8.6 x 108 Hz. What is the energy of one photon of this
(e) 7.7 x 10-43 J
2.3 x 10-34 J
5.7 x 10-25 J
1.7 x 10-16 J
1.2 x 10-15 J 5. In a constant-pressure calorimeter, 55.0 mL of 0.320 M Ba(OH)2 added to 55.0 mL of
0.640 M HCl. The reaction caused the temperature of the solution to rise from 22.89 °C
to 27.25 °C. If the solution has the same density and specific heat as water (1.00 g/mL
4.18 J/g·°C, respectively),what is ΔH for this reaction per mole of H2O
(e) -57.0 kJ/mol
143 kJ/mol 2 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 6. If you combine 270.0 mL of water at 25.00 °C and 140.0 mL of water at 95.00 °C, what is
the final temperature of the mixture? Use 1.00 g/mL as the density of water.
(e) 53.42 °C
23.67 °C 7. If a system has 345 J of work done to it, and releases 5.26 kJ of heat into its
surroundings, what is the change in internal energy of the system?
(e) 5.61 x 103 J
4.92 x 103 J
-4.92 x 103 J
-350. J 8. When 1356 J of heat energy is added to 32.5 g of hexane, C6H14, the temperature
increases by 14.0 °C. Calculate the molar heat capacity of C6H14
(e) 2.98 J/mol·°C
287 J/mol·°C 9. Platinum, which is widely used as a catalyst, has a work function (the minimum energy
needed to eject an electron from the metal surface) of 9.05 x 10¯19 J. What is the longest
wavelength of light which will cause electrons to be emitted? (a)
(e) 2.20 x 10-7 m
4.55 x 10-6 m
5.65 x 102 m
1.37 x 1015 m
1.22 x 106 m 10. Calculate the frequency of a photon absorbed when the hydrogen atom undergoes a
transition from n1 = 2 to n2 = 4.
(e) 2.056 x 106 Hz
2.742 x 106 Hz
6.169 x 1014 Hz
8.226 x 1014 Hz
3.234 x 1015 Hz 11. Which scenario will result in the greatest decrease in energy for the system?
(e) The system releases 234 cal of heat and has 430 J of work done on it.
The system gains 904 J of heat and does 23.9 cal of work.
The system does 321 cal of work and loses 2.34 kJ of heat.
The system has 1.09 kJ of work done to it and loses 892 cal of heat.
The system gains 1000. cal of heat and does 4.184 kJ of work. 3 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 12. Solid strontium chloride (SrCl2) is added to an aqueous solution of silver nitrate,
precipitating silver chloride. Given that the standard enthalpy of reaction (ΔHºrxn) is
-182.97 kJ determine the standard heat of formation (ΔHºf) for silver ions (Ag+(aq)).
SrCl2(s) + 2Ag+(aq) + 2NO3-(aq) → Sr2+(aq) + 2AgCl(s) + 2NO3-(aq)
Species SrCl2(s) Sr2+(aq) Ag+(s) AgCl(s) NO3-(aq) Cl-(aq) ΔHºf
(kJ/mol) -828.4 -545.51 312.47 -127.03 -206.57 -167.46 (a)
(e) -719.5 kJ/mol
-348.47 kJ/mol 13. Calculate the enthalpy change for the reaction NO(g) + O(g) → NO2(g) from the following
NO(g) + O3(g) → NO2(g) + O2(g)
ΔH = -198.9 kJ
O3(g) → 3/2O2(g)
ΔH = -142.3 kJ
O2(g) → 2O(g)
ΔH = 495.0 kJ (a)
(e) -551.6 kJ
438.4 kJ 14. Given the reaction below, and an excess of O2(g) how many grams of SO2(g) would be
needed for the reaction to release 283.4 kJ of heat?
2SO2(g) + O2(g) → 2SO3(g)
(e) ∆H = -198.4 kJ Impossible, this reaction is endothermic.
112.1 g 15. Which is not an example of the wave-particle duality; where a particle may act like a
wave, or a wave may act like a particle?
(e) The diffraction patterns of electrons passes through aluminum crystals.
The refraction of a beam of light passing from air into water.
The photoelectric effect.
The line spectrum for the emission of light from a hydrogen atom. 4 of 12 Fall 2015 Exam 2-A
CHEM 200 Fall 2016 October 17, 2015
Exam 2-B November 25, 2016 answers on the scantron sheet using a #2 pencil and also mark your answers 16. Which one of the following equations represents the formation reaction of CH3OH(l)?
(a) C(g) + 2H2(g) + ½O2(g) → CH3OH(l) C(s) + 4H(g) + O(g) → CH3OH(l)
m version on your(b)
scantron. (c) C(graphite) + 4H(g) + O(g) → CH3OH(l)
(d) C(diamond) + 4H(g) + O(g) → CH3OH(l)
that has a wavelength of 405 nm. Calculate
(e) C(graphite) + 2H2(g) + ½O2(g) → CH3OH(l) are read with a
photons from this type of laser.
the energy 17. A sprinter must average 24.0 mi/h to win a 100-m dash in 9.30 s. What is his wavelength
at this speed if his mass is 8.45 x 104 g? (1 km = 0.62137 mi)
(e) 7.31 x 10¯37 m
3.26 x 10¯37 m
5.08 x 10¯30 m
1.34 x 10¯30 m
1.54 x 10¯30 m −28
th a mass of 18.
atom. Ain the speed of an
if the uncertainty
3 m/s, theto
determines the position
the of an
in its position
is at least:
g) uncertainty in the velocity of the
asured as 6.39×10
What (a) 1.6 x 10¯8 m
(b) 6.6 x 10¯8 m
(c) 17 m
(d) 66 m
s no uncertainty in
19. Consider the set of isoelectronic atoms and ions: A+, B2—, C—, D3—, E3+. Which
arrangement of relative radii is correct? E3+ < A+< the
B2— < D3—of spin for an electron orbiting an
m number is used to(a)describe
(e) A+ < E3+ < C— < B2— < D3—
D3— < B2— < C— < A+ < E3+
C— < B2— < D3— < E3+ < A+
A+ < E3+ < D3— < B2— < C— 20. Which of the following elements has the largest fourth ionization energy (IE4)?
(e) Tl of copper metal is
at 100.0°C. It is dropped into a coffee cup
ntaining 50.0 g of water at a temperature of 20.0°C. After stirring, the final
apacity of water is 4.18 J/g•K, what is the heat capacity of the copper in J/K?
XeF4 f these choices is correct.
5 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 22. What is the average bond order for the phosphate ion?
2 23. From the list of molecules below, identify those which are polar molecules. Mark all
CH2O 24. Which of the molecules below would have the largest magnitude lattice energy?
25. An atom of element number 35 (Br) is n its ground electronic state. Which one of the
following set of quantum number could not apply to any of its electrons?
(e) n= 4 ml= -2
n= 3 l=2
n= 4 l= 0 ms = +1/2
n= 1 l= 0
n= 5 l= 2 26. Identify the element from Period 4, which has the successive ionization energies
Ionization 1st 2nd 3rd 4th 5th 6th 7th 8th Energy
(kJ/mol) 1314 3389 5298 7471 10,992 13,329 71,345 84,087 (a)
Br 6 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 27. The shape of an atomic orbital is associated with: (a)
(e) the principal quantum number (n).
the angular momentum quantum number (l).
the magnetic quantum number (ml).
the spin quantum number (ms).
the magnetic and spin quantum numbers, together. 28. Which of the following is a correct set of quantum numbers for an electron in a 5f orbital?
(e) n = 5, l = 3, ml = +1
n = 5, l = 2, ml = +3
n = 4, l = 3, ml = 0
n = 4, l = 2, ml = +1
n = 5, l = 4, ml = 3 29. Select the correct electron configuration for Ag (Z =47).
30. Which of the following electrons configurations is impossible? There is only one correct
1s12s22p63s23p4 31. Which of the following elements is the least electronegative?
(e) Sr Fall 2013 Name__________________________________ Exam 3 November 16, 2013
Lab Sect. No.__________ 32. Identify the elements whose Lewis symbol has been properly depicted. Mark all correct 6. Identify
the elements whose Lewis symbol has been properly depicted. Mark all correct
! 7. Which of bonds below is the strongest?!
! 7 of 12
8. For the reaction below, determine ∆Hrxn (in kJ) based on the provided bond energies:
H−C 413; C−C 347; C＝C 614; C−Br 276; H−Br 363 (all in kJ/mol)!
(a) 288 kJ! (d) Linear!
(c) C＝C! (e) Trigonal pyramidal
whose central November
atom has a formal
charge of -1.!
8. For the reaction below,
∆Hrxn (in kJ) based on the provided bond energies:
below, determine the Hrxn (in kJ) based on the provided bond energies:
33. For the
H−C 413; C−C 347; C＝C4 614; C−Br 276; H−Br 363 (all in kJ/mol)!
(a) 288 kJ!
(b) 555 kJ!
(c) 59 kJ!
(d) -555 kJ!
the resonance hybrid Lewis structure of carbonate (CO32-) which statement
below is correct?!
9. Which of the molecules
hybrid is longer than a regular C−O bond.!
(a) CO! Hrxn(b) The bond413
276in the resonance
length of each 347
bond between carbon
hybrid is longer than a regular C＝O bond.!
ThekJresonance hybrid Lewis structure is the result of the rotation of the molecule.!
(d) SO2! (a)(c)288
ThekJlength of the bonds between carbon and oxygen vary continuously in the
carbon and oxygen in the resonance hybrid are weaker than a
10. Which of the following elements is the
regular C−O bond.
34. For the molecule, ClF3, how many lone pairs of electrons are there on the central
molecules listed below have a central atom that is not obeying the octet rule for
(d) Sc!Lewis structures? Mark all correct answers.!
(a)(a)0 SO ! ! ! ! ! ! ! ! 2 (b)(b)1 CH2O!
11. For the molecule ClF
how many lone pairs of electrons are there on the central chlorine
(a) 0! (e) H2O2
(c) 2!35. What are the formal charges of each of the atoms in the molecule below?
3! What are the formal charges of each of the atoms in the molecule below?!
, C= =0 0, N, N= =
(a)(a)OO= =-1-1, C
(b) O = -1 , C = 0 , N = +2+2!
(c)(c)OO= =+1+1, C
, C= =0 0, N, N= =
(d) O = +1 , C = 0 , N =
(e)(e)OO= =+2+2, C
! ! ! 36. Which of the molecules listed below have a central atom that is an expanded octet for
H2O2 8 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 BLANK PAGE 9 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 BLANK PAGE 10 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 BLANK PAGE 11 of 12 CHEM 200 Fall 2016 Exam 2-B November 25, 2016 BLANK PAGE 12 of 12 ...
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