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Important topics to review or the final:

- Enthalpy and energy calculations: calorimetry, heats of reaction etc

- Molecular shape aspects: m, l and n aspects of elements and atoms

- Types of bonds and their characteristics

- Periodic table trends and group characteristics

- Non Ideal gas law- Van Der Waal’s equation

Part I: Multiple Choice: (3 pts each).

1. Calculate the density of SO3 gas at 350C and 715 torr in g/La) 0.0285 b) 1.43 c) 2.15 d) 2.98

2. What is the chemical formula of a gas if it has a pressure of 1.40 atm and a density of 1.82 g/L at 270C?a) CO2 b) CO c) CH4 d) O2

3. Calculate the amount of heat released to the environment when 245 g of steam at 1400C is cooled -150C.

4. Pi bonds are formed through the overlap of what type of orbitals?a) s b) p c) sp d) sp2

5. What intermolecular force is most important in explaining why glucose, C6H6O6 is soluble in water?a) Hydrogen bonding b) Ion-dipolec) London dispersion forces d) Dipole-dipole

6. What intermolecular force is most responsible for molecular iodine, I2, being a solid at room temperature?a) Hydrogen bonding b) Ion-dipolec) London dispersion forces d) Dipole-dipole

7. What gives ionic liquids their low melting point?a) Low molecular weight b) No ionic bondingc) High lattice energy d) Large ions and shape mismatch between them

8. Which atom can accommodate an octet of electrons, but doesn’t necessarily have to accommodate an octet?

a) N b) C c) H d) B

9. Which atom in each group (I and II) has the smallest atomic radius?

(I) Sr, In, I (II) N, P, As

a) Sr; N b) Sr, As c) I; N d) I; As

10. Arrange the ions N3–, O2–, Mg2+, Na+, F– in order of increasing ionic radius starting with the smallest first.

a) Mg2+, Na+, F– , O2–, N3– b) N3–, Mg2+, O2–, Na+, F–

c) N3–, O2–, Mg2+, F– , Na+ d) N3–, O2–, F– , Na+, Mg2+

11. Which element has the most negative electron affinity?

a) B b) C c) F d) Ne

12. Which alkaline earth metal reacts the most vigorously with water at room temperature?

a) Be b) Ca c) Ba d) Sr

13. Metals tend to react with the halogens to form metal halides. What is the reactivity order for the halogens?

a) F2 > Cl2 > Br2 > I2 b) Cl2 > F2 > Br2 > I2

c) Br2 > I2 > Cl2 > F2 d) I2 > Br2 > Cl2 > F2

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14. A reactive element with a relatively high electronegativity would be expected to have a relativelya) small negative electron affinity and a relatively low ionization energy.b) small negative electron affinity and a relatively high ionization energy.c) large negative electron affinity and a relatively low ionization energy.d) large negative electron affinity and a relatively high ionization energy.

15. Element A has an electronegativity of 0.8 and element B has an electronegativity of 3.0. Which statement best describes the bonding in A3B?a) The AB bond is largely covalent with a - on A.b) The AB bond is largely covalent with a on A.c) The compound is largely ionic with A as the cation.d) The compound is largely ionic with A as the anion.

16. NO2– is expected to have

a) bonds flickering back and forth between single bonds and double bonds.

b) one single and one double bond.

c) two double bonds.

d) two identical bonds intermediate between a single and a double bond.

17. In the Lewis structure for SCl2O, the formal charges are: on S, on the Cl atoms, and on O.

a) 0, 0, 0 b) +1, 0, –2 c) +1, 0, –1 d) +4, –1, –2 e) –1, 0, +1

18. Based on VSEPR theory, which should have the smallest XAX bond angle?

19. The molecular geometry of phosphorus trichloride PCl3 is .

a) trigonal planar b) trigonal pyramidal c) tetrahedral

d) bent e) T–shape

20. What is the approximate Cl–P–Cl bond angle in phosphorus trichloride PCl3?

a) 90˚ b) 109.5˚ c) 120˚ d) 180o

21. Which covalent bond is the most polar?

a) C–F b) N–F c) F–F d) Cl–F

22. Which one of the following compounds produces a basic solution when dissolved in water?

a) SO2 b) Na2O c) CO2 d) OF2

23. For an electron in a given atom, the larger n, the

a) larger the average distance from the nucleus and the higher the orbital energy.

b) larger the average distance from the nucleus and the lower the orbital energy.

c) smaller the average distance from the nucleus and the higher the orbital energy.

d) smaller the average distance from the nucleus and the lower the orbital energy.

624. The bond angles marked a, b, and c in the molecule below are approximately , , and ,

respectively.

a) 109.5˚, 109.5˚, 109.5˚

c) 109.5˚, 109.5˚, 90˚ d) 90˚, 90˚, 90˚

e) 109.5˚, 109.5˚, 120˚

Part-II: For full credit, show all your work legibly, include units, and report your answer to the correct number of significant figures. No work shown = 0 points.

25. Complete and balance the following reaction equations. For full credit, include the phase (s, l, g, or aq) for all reactants and products.

A. (4 pts) Na (s) + H2O (l)

B. (4 pts) CO2 (aq) + Na2CO3 (aq) + H2O (l)

C. (4 pts) CaO (s) + H2O (l)

26. A. (6 pts) Use average bond enthalpies to estimate the enthalpy for the following gas phase reaction. Note that O=O is O2.

B. (2 pts) This reactionheat and is .

i. produces; exothermic ii. absorbs; endothermic

iii. absorbs; exothermic iv. produces; endothermic

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b) 120˚, 109.5˚, 120˚

27. A. (2 pts) Draw the Lewis structure for PCl3F2. Include lone pairs.

B. (2 pts) The more electronegative are the atoms bonded to the central atom, the less are the repulsions between the electron pairs in the bonds. On the basis of this statement, draw the most probable structure of the molecule PCl3F2. If you did not arrive at a Lewis structure in part A, use this:

FS

F

C. (2 pts) What is the name of the shape or geometry of the molecule?

D. (3 pts) indicate the bond angles in the molecule. “A” refers to the central atom.

Bond angleF – A – Cl

Cl – A – Cl

F – A – F

E. (1 pts) Is this molecule polar or nonpolar?

If the molecule is polar, indicate on the drawing in part B the direction of the dipole moment using the notation: .

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Cl

F

F Cl

828. A. (6 pts) The inflation of an “air bag” when a car experiences a collision occurs by the explosive

decomposition of sodium azide, NaN3, which yields nitrogen gas that inflates the bag. The following Lewis structures can be drawn for the azide ion, N3

–. Identify each as valid or invalid. For the invalid structures clearly explain why the structure is invalid.

label Lewis structure valid or invalid? Explanation of why the structure is invalid.

a N N N-

b N N N-

c N N N-

d N N N-

B. (2 pts) Which one of the structures is best? a b c d

C. (2 pts) Clearly and completely, but briefly explain your answer in B.

29. A. (4 pts) Draw all resonance structures for the nitrate ion NO3–.

B. (1 pt) One of two resonance structures for nitrogen dioxide NO2 is shown. O N O

Nitrogen–oxygen bonds in NO2 are than are those in the nitrate ion.

i) shorter & stronger ii) longer & weaker iii) shorter & weaker

iv) longer & stronger v) none of the above.

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Pe riodic Table of t he Element s1 A 8 A 1 1 8 1 2 A 3 A 4 A 5 A 6 A 7 A 2H 2 1 3 1 4 1 5 1 6 1 7 He

1.01 4.00

3 4

8 B

5 6 7 8 9 1 0 Li

6.94 Be

9 .0 1B

10 .8

C 12 .0

N 14.0

O 1 6 .0

F 19.0

Ne 2 0 .21 1 1 2 3 B 4 B 5B 6 B 7 B 1 B 2 B 1 3 14 1 5 1 6 1 7 1 8

Na Mg 3 4 5 6 7 8 9 1 0 1 1 1 2 Al Si P S Cl Ar

23.0 24.3 27 .0 2 8 .1 31.0 3 2 .1 3 5 .5 39.9

1 9 2 0 2 1 2 2 23 2 4 2 5 26 2 7 2 8 2 9 3 0 3 1 32 3 3 3 4 3 5 3 6 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

3 9 .1 40.1 45 .0 47 .9 5 0 .9 52.0 54.9 5 5 .8 58.9 58 .7 63.5 65.4 69 .7 72 .6 74.9 79.0 7 9 .9 83.8

3 7 3 8 3 9 4 0 4 1 4 2 4 3 4 4 4 5 4 6 4 7 4 8 4 9 5 0 5 1 5 2 5 3 5 4 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

85.5 8 7 .6 88.9 91.2 9 2 .9 95 .9 (9 8 ) 101 103 106 108 1 1 2 115 1 1 9 122 128 1 2 7 131

5 5 5 6 5 7 7 2 73 7 4 7 5 76 7 7 7 8 7 9 8 0 8 1 82 8 3 8 4 8 5 8 6 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

133 1 3 7 1 3 9 178 1 8 1 184 186 190 192 195 197 2 0 1 2 0 4 2 0 7 209 ( 2 09) ( 210 )

( 222)

8 7 8 8 8 9 1 0 4 1 0 5 106 1 0 7 108 109 1 1 0Fr Ra Ac Rf Db Sg Bh Hs Mt Ds

( 2 23) 226 2 2 7 ( 2 61) (2 6 2 ) ( 263 ) ( 2 62) ( 265) ( 266 ) (2 8 1 )

Lant hanides58 5 9 6 0 6 1 6 2 6 3 6 4 6 5 6 6 67 6 8 6 9 7 0 7 1 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

14 0 141 1 4 4 ( 145) 150 1 5 2 157 159 1 6 2 1 6 5 1 6 7 169 1 7 3 175

Ac t inides90 9 1 9 2 93 9 4 9 5 9 6 9 7 9 8 99 100 1 0 1 102 1 0 3Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

23 2 231 2 3 8 ( 237 ) ( 244 ) ( 2 43) ( 247) ( 247 ) ( 2 51) (2 5 2 ) ( 257 ) ( 2 58) ( 259 )

( 2 60)

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