Chemistry 106: General Chemistry
Syracuse University Project Advance
Exam #2, Fall 2003
NameDate
The last page of each examination is a periodic table.
c = 3.00 x 108 m/sec
h = 6.63 x 10-34 Js
mp = 1.67 x 10-24 g (mass of proton)
Rydberg Constant (RH) = 2.18 x 10-18 J
(1)Hydrogen peroxide, H2O2, can be prepared in a process whose overall change is:
H2(g) + O2(g) ------> H2O2(l)
Calculate the enthalpy change for the reaction above using the following data.
H2O2(l) ------> H2O(l) + 1/2 O2H = -98.0 kJ
2 H2(g) + O2(g) ------> 2H2O (l)H = -571.6 kJ
(a) -670 kJ
(b) -474 kJ
(c) -523 kJ
(d) -384 kJ
(e) -188 kJ
(2)Ethanol (molar mass = 46.05 g/mol), C2H5OH, is mixed with gasoline and sold as gasohol. Use the following to calculate the grams of ethanol needed to provide 293 kJ of heat:
C2H5OH(l) + 3 O2(g) ------> 2 CO2(g) + 3 H2O(g)H = -1235 kJ
(a) 10.9 g
(b) 21.8 g
(c) 32.7 g
(d) 43.6 g
(e) 54.5 g
(3)Phosphoric acid, H3PO4, can be prepared by the reaction of phosphorus(V) oxide, P4O10, with water
1/4 P4O10(s) + 3/2 H2O(l) ------> H2PO4(aq)H = -113.2 kJ
What is H for the reaction involving 1 mol of P4O10?
(a) +113.2 kJ
(b) +28.3 kJ
(c) -28.3 kJ
(d) -452.8 kJ
(e) -905.6 kJ
(4)Which one of the following will have the greater kinetic energy?
(a) A 10 kg object traveling at 5 m/s.
(b) a 5 kg object traveling at 10 m/s.
(c) both of these have the same kinetic energy.
(d) not enough information is provided to answer the question.
(5)Given that Hf for MgCl2 is -641.6 kJ/mol and Hf for KCl is -435.9 kJ/mol, calculate Hrxn for the following equation:
2 K(s) + MgCl2(s) ------> 2 KCl(s) + Mg(s)Hrxn = ?
(a) +205.7 kJ
(b) -205.7 kJ
(c) +230.2 kJ
(d) -230.2 kJ
(e) +1077.5 kJ
(6)A chemical reaction that absorbs heat from the surroundings is said to be and has a value of H.
(a) endothermic, positive
(b) endothermic, negative
(c) exothermic, negative
(d) exothermic, positive
(e) isothermic, zero
(7)Which of the following has the longest wavelength?
(a) an electron traveling at x meters per second.
(b) a proton traveling at x meters per second.
(c) a proton traveling at 2x meters per second.
(d) they all have the same wavelength.
(e) not enough information is provided.
(8)Which of the following sets of quantum numbers is/are possible for an electron in an atom?
I. n = 4, l = 4, ml = 3, ms = +1/2
II. n = 1, l = 0, ml = 0, ms = -1/2
III. n = 2, l = 0, ml = -2, ms = +1/2
(a) None are possible
(b) I and II
(c) I
(d) II
(e) III
(9)Indium compounds emit a blue-violet color when placed in a flame. The emission responsible for this blue-violet color has a wavelength of 451 nm. Calculate the energy of a single photon of this wavelength.
(a) 2.99 x 10-40 J
(b) 1.47 x 10-27 J
(c) 4.41 x 10-19 J
(d) 2.99 x 10-31 J
(e) 1.47 x 10-36 J
(10)How many unpaired electrons are in a ground state atom of phosphorus?
(a) 0
(b) 1
(c) 2
(d) 3
(e) None of the above.
(11)The number of core electrons shielding the valence-shell electrons of an atom of aluminum from the nucleus is:
(a) 13
(b) 10
(c) 6
(d) 3
(e) 0
(12)Calculate the energy (joules per particle) of a photon of wavelength 22.5 nm (Plancks Constant is 6.63 x 10-34 Js)
(a) 1.13 x 1017
(b) 1.13 x 1013
(c) 8.84 x 10-11
(d) 8.84 x 10-18
(e) None of the above.
(13)What is the wavelength of light emitted when the hydrogen atom undergoes a transition from level n = 5 to level n = 2? (RH = 2.180 x 10-18 J)
(a) 663 nm
(b) 833 nm
(c) 546 nm
(d) 521 nm
(e) 434 nm
(14)The square of the wavefunction, 2, of an electron in an atom
(a) describes the energy of the electron.
(b) specifies the momentum for the electron.
(c) gives the probability of finding the electron in a region of space.
(d) is proportional to the velocity of the electron.
(e) is inversely proportional to the distance between the electron and the nucleus.
(15)From the Bohr model of the hydrogen atom, we can conclude that the energy required to excite an electron from the n = 2 to the n = 3 level is the energy to excite an electron from the n = 3 to the n = 4 level.
(a) less than
(b) greater than
(c) equal to
(d) either equal to or less than
(e) either equal to or greater than
(16)All of the following statements about quantum numbers are true except
(a) n has integral values from 1 to infinity.
(b) l has values from 1 to infinity.
(c) ml has 2l + 1 values
(d) ml has values of +1 to -1, including zero.
(e) ms has values of + 1/2 and - 1/2.
(17)Which of the following combinations of quantum numbers are permissible?
nlmlms
I.331-1/2
II.421-1/2
III.321+1/2
(a) I only
(b) II only
(c) III only
(d) I and II only
(e) II and III only
(18)What is the maximum number of electrons in the n = 3 quantum level?
(a) 3
(b) 5
(c) 7
(d) 9
(e) 18
(19)Which of the following atoms has the smallest atomic radius?
(a) Sr
(b) Mg
(c) P
(d) I
(e) Ne
(20)Which of the following atoms designated by electronic configuration has the highest ionization energy?
(a) [Ne] 3s23p2
(b) [Ne] 3s23p3
(c) [Ar] 3d104s24p3
(d) [Kr] 4d105s25p3
(e) [Xe] 4f145d106s26p3
(21)Which one of the following elements would be expected to have the largest atomic radius?
(a) Li
(b) Cs
(c) F
(d) Br
(e) I
(22)In general, atomic radii
(a) decrease from left to right in a period and increase down a group.
(b) increase from left to right in a period and decrease down a group.
(c) increase from left to right in a period and increase down a group.
(d) decrease from left to right and decrease down a group.
(e) None of the above.
(23)All of the following is isoelectronic except
(a) S2-
(b) Ar
(c) K+
(d) Cl-1
(e) Na+
(24)Which of the following statements about the alkali metals (Group 1) is not correct?
(a) Electron affinities decrease going down the group (from smaller to larger elements).
(b) Ionization energies decrease going down the group (from smaller to larger elements).
(c) Chemical reactivity decreases going down the group (from smaller to larger elements).
(d) The second ionization energy for each one is much greater than the first ionization energy.
(e) Each one can attain a noble gas configuration by losing an electron.
CHE 1061 Fall 2003 Exam Questions