Name:______

CHEMISTRY 1211 Fall 2007

EXAM #3

This exam is 9 pages long. Please read through all of the questions first and ask about anything you do not understand. You will have one hour and 15 minutes to complete this exam. Exams will be picked up at the end of the class period. No late exams will be accepted!

You are allowed to use a calculator. The exam is worth a total of 100 points, each question is worth 5 points. Be sure to record all answers on the scantron sheet.

Included in this exam is a periodic table, which should be stapled to the back of the exam.

CHEATING IS NOT ALLOWED. ANYONE CAUGHT CHEATING WILL BE TURNED OVER TO JUDICIAL AFFAIRS.

Good Luck!

q=msT q=CT

Specific Heat for water 4.184 J/gC c=

E=h 

1  1 1   R    2 2    n1 n2 

R= 1.096776x107 m-1 2

1.) A 51.6 mL dilute solution of acid at 23.85C is mixed with 48.5 mL of a dilute solution of base also at 23.85C in a coffee cup calorimeter. After the reaction occurs, the temperature of the resulting mixture is 27.25C. The density of the final solution is 1.03 g/mL. Calculate the amount of heat evolved. Assume the specific heat of the solution is 4.184 J/gC. The heat capacity of the calorimeter is 23.9J/C.

a.) 3.05 kJ b.) 1.55 kJ c.) 5.49 kJ d.) 0.837 kJ e.) 14.6 kJ 3

2.) Which statement concerning state functions is false?

a.) A change in a state function describes a difference between two state and is independent of the process by which the change occurs. b.) State functions are represented by capital letters c.) Differences in state functions are often described by an arbitrary scale

d.) The change in a quantity X is described as X = Xfinal - Xinitial

e.) If the initial value is greater than the final value for X = Xfinal- Xinitial then X is positive.

3.) Given the standard heats of formation for the following compounds, calculate H for the following reaction:

CH4 (g) + H2O (g)  CH3OH (l) + H2 (g) H -75 -242 -238 0 (kJ/mol)

a.) +79 kJ b.) -79 kJ c.) +594 kcal d.) -594 kcal e.) -405 kJ

4.) Given the H for the reaction above calculate the amount of heat evolved if 10.0 grams of methane gas, CH4 reacted with steam to produce methanol, CH3OH (l) and H2 gas.

a.) 78.2 kJ b.) 253 kJ c.) 347 kJ 4

d.) 48.9 kJ e.) 125 kJ 5.) How much heat is released when 6.38 grams of Ag (s) reacts by the equation shown below at standard state conditions?

4Ag (s) + 2H2S (g) + O2 (g)  2Ag2S (s) + 2H2O (l)

Substance Hf (kJ/mol) Ag(s) 0 H2S (g) -20.6 O2(g) 0 Ag2S (s) -32.6 H2O (l) -285.8

a.) 8.80 kJ b.) 69.9 kJ c.) 22.1 kJ d.) 90.8 kJ e.) 40.5 kJ

6.) How much heat is absorbed in the complete reaction of 3.00 grams of SiO2 with excess carbon in the reaction below? H for the reaction is +624.6 kJ.

SiO2 (g) + 3C(s)  SiC (s) + 2CO (g)

a.) 366 kJ b.) 1.13 x105 kJ c.) 5.06 kJ 4 d.) 1.33x10 kJ e.) 31.2 kJ 5

7.) From the following data at 25C. Calculate H for the reaction below.

H2 (g) + Cl2 (g)  2HCl (g) H = -185 kJ

2H2 (g) + O2 (g)  2H2O(g) H = -483.7 kJ

4HCl (g) + O2 (g)  2Cl2 (g) + 2H2O (g) H = ?

a.) +299 kJ b.) -114 kJ c.) -299 kJ d.) +114 kJ e.) -86.8 kJ

8.) From the following data at 25C. Calculate H for the reaction below.

SO3 (g) + H2O(l)  H2SO4 (l) H = -133 kJ

Pb (s) + PbO2 (s) + 2H2SO4 (l)  2PbSO4(s) + 2H2O (l) H = -509 kJ

Pb(s) + PbO2 (s) + 2SO3 (g)  2 PbSO4(s) H = ?

a.) +376 kJ b.) -376 kJ c.) -642 kJ d.) -243 kJ e.) -775 kJ 6

9.) What is the wavelength in meters of radiation with a frequency = 4.80x1013 s-1.

-8 a.) 3.48x10 m b.) 1.60x10-1 m c.) 1.44x1022 m d.) 6.25x10-6 m e.) 7.10x10-7 m

10.) The emission spectrum of gold shows a line of wavelength 2.676x10-7 m. How much energy is emitted as the excited electron falls to a lower energy level?

-19 a.) 7.43x10 J/atom -20 b.) 1.07x10 J/atom -19 c.) 6.05x10 J/atom -20 d.) 3.60x10 J/atom -20 e.) 5.16x10 J/atom 7

11.) The Heisenburg Uncertainty Principle states that ______.

a.) no two electrons in the same atom can have the same set of four quantum numbers

b.) two atoms of the same element must have the same number of protons

c.) it is impossible to know both the position and momentum of an electron simultaneously

d.) electrons of atoms in their ground states enter energetically equivalent set of orbitals singly before they pair up in any orbital of the set

e.) charged atoms (ions) must generate a magnetic field when they are in motion

12.) Identify the following orbital

a.) dx2-y2 b.) dz2 c.) pz d.) dxy e.) fz

13) Which element has the electron configuration:

1s22s22p63s23p63d104s24p3

a.) V b.) Ca c.) P d.) As e.) Se 8

14) An element has the outermost electron configuration ns2np5 The element could be ______.

a.) Si b.) P c.) Br d.) Ar e.) Mn

15.) The number of electrons present in the p orbital in the outmost electron shell (major energy level, n) of the halogen atoms is ______.

a.) One b.) two c.) six d.) seven e.) five

16.) Which element has the smallest radius?

a.) F b.) Cl c.) Br d.) I e.) At

17.) Arrange the following in order of increasing atomic radii

Sr, Rb, Sb, I, In

a.) Rb < Sr < In < Sb < I b.) I < Sb < In < Rb < Sr c.) In < Sb < I < Sr < Rb d.) Sb < I < In < Sr < Rb e.) I < Sb < In < Sr < Rb

18.) Arrange the following in order of decreasing ionization energy.

Rb, In, Sn, Sb, As

a.) Sb > Sn > In > As > Rb b.) As > In > Sn > Sb > Rb c.) Rb > As > Sb > Sn > In d.) As > Sb > Sn > In > Rb e.) As > Sn > Sb > In > Rb 9

19.) Arrange the following set of ions in order of decreasing ionic radii

Al3+ Ga3+ Ca2+ Rb+ K+ a.) Rb+ > Ga+3 > Ca+2 > K+ > Al+3 b.) Rb+ > K+ > Ca+2 > Al+3 > Ga+3 c.) Ga+3 > Al+3 > Ca+2 > Rb+ > K+ d.) Rb+ > Ca+2 > K+ > Ga+3 > Al+3 e.) Rb+ > K+3 > Ca+2 > Ga+3 > Al+3

20.) Arrange the following in terms of increasing electronegativities.

At, Bi, Cl, F, I a.) At < Bi < Cl < F < I b.) F < Cl < Bi < I < At c.) Bi < At < I < Cl < F d.) F < Cl < I < At < Bi e.) At < Bi < I < Cl < F