Download CHEMISTRY 1A

100 Points
CHEMISTRY 1A
Exam 4
Name___________________________
SHOW ALL OF YOUR WORK!
c = 3.00108 m/s; h = 6.6310-34 J·s; mass e- = 9.1110-31 kg; R = 1.097107m-1;

h
mv
1. A sample of gas occupies 2.85 L at -23C and a pressure of 575 torr. Calculate the new pressure, in
atm., if the temperature is raised to 92C and the new volume is 745 mL. (760 torr = 760 mmHg = 1 atm)
(5)
2. Balloons built for trans-Atlantic flights contain 1.2107 L of helium. If the pressure is 737 mmHg at
35C calculate the mass of helium in the balloon.
(5)
3. A 6.0 L gaseous compound containing only carbon, hydrogen and nitrogen was combusted in pure
oxygen, 33.6 L of CO2(g), 57.0 L of H2O(g), and 23.0 L of N2(g) were produced with all gases measured
at STP. Determine the empirical formula. (!! For 5 extra points determine the molecular formula of the
gaseous compound!!)
(10)
4. A mixture of 14.0 grams He, 90.0 grams of Ne, and 5.00 mole O2 in a 45.0 liter container has a total
pressure of 39.0 atm. Calculate the partial pressure of each gas.
(10)
5. When 3.515 g of solid M(III)carbonate is heated, the CO2(g) evolved has a pressure of 1030 torr at
172C in a 975. mL flask. Determine the identity of metal M.
(10)
Mx(CO3)y(s)  MxOy(s) + yCO2(g)
6. Fill in the blanks.
(10)
a. The quantum number, n, describes the _________and _________of an atomic orbital.
b. The shape of an atomic orbital is given by the quantum number _________.
c. The maximum number of orbitals that may be associated with the following set of quantum numbers
n = 5 and l = 3 is _________.
d. The maximum number of electrons that may be associated with the quantum number set n = 4, l = 1,
and ml = 1 is _________.
7. A photon of light is emitted from a hydrogen atom when the electron de-excites from the n = 5 level.
The frequency of the photon is 6.451013s-1. Determine the final quantum number state of the electron.
(8)
8. An electron has a kinetic energy of 1.2510-19 J. Calculate the De Broglie wavelength of the electron.
(10)
9. Rank the following in order of :
a. Increasing atomic radius. C, O, F, and Na
b. Increasing first ionization energy. Si, N, O, and F
c. Increasing radius. Mg+2,Al+3, S-2, Cl-, and Na+
d. Increasingly more negative electron affinity. C, N, O, and F
(15)
10. Write the spectroscopic electronic configuration for Co+3. How many unpaired electrons does the ion
have? Is the ion diamagnetic or paramagnetic?
(8)
11. Using positive ml and ms values first, determine the set of quantum numbers or the element
represented. Show Your Work!!!!!!!
(12)
a. 33As
b. (4, 0, 0, -1/2)
c. 69Tm
d. (4, 2, -2, 1/2)