Supplemental Instruction
Iowa State University / Leader: / Ryan Gale
Course: / Chem 177
Instructor: / Miller/Bonaccorsi/Greenbowe
Date: / 11/11/12
1.) How does effective nuclear charge increase on the periodic table?
a.) Up columns, to the left of rows b.) Up columns, to the right of rows
c.) Down columns, to the left of rows d.) Down columns, to the right of rows
2.) Which atom in each group (I and II) has the smallest atomic radius?
(I) Se, F, P (II) Ga, K, Te
a.) Se; Ga b.) F; K c.) F; Ga d.) P; Te
3.) Answer True or False to the following. If the sentence is false, correct it.
- Ionization energies are always negative quantities.
- Oxygen has a larger first ionization energy than fluorine.
- The second ionization energy of an atom is always greater than its first ionization energy.
4.) What group on the periodic table has positive electron affinities for all of its elements? Which group has very negative electron affinities for all of its elements? Which group has slightly negative electron affinities for all of its elements?
a.) –Noble gases, alkali metals, chalcogens
b.) Chalcogens, alkali metals, noble gases
c.) Halogens, alkali metals, noble gases
d.) Noble gases, halogens, alkali metals
5.) What is the definition of electronegativity?
a.) The energy change that occurs when an electron is added to a gaseous atom.
b.) The minimum energy required to remove an electron from the ground state of the isolated gaseous atom or ion
c.) The amount of energy required to break a particular bond in 1 mole of gaseous atoms.
d.) The ability of an atom in a molecule or solid to attract electrons to itself.
6.) What elements follow the octet rule absolutely with no exceptions?
- Al b. Ar c. C d. S
7.) From the following elements, which compounds are unlikely to form covalent bonds?
S, H, K, Ar, Si
- H2S b. SiH4 c. ArSi3 d. K2S
8.) Which of the following molecules is nonpolar?
a.) IF b.) CS2 c.) PCl3 d.)SO3
9.) NO2- is expected to have
- Bonds flickering back and forth between single and double bonds.
- One single and one double bond.
- Two double bonds.
- Two identical bonds intermediate between a single and a double bond.
10.) Which of the following molecules do not obey the octet rule?
a.) NO b.) BF3 c.) ICl2- d.) XeF4
11.) What is the formal charge around the central atom of the molecules O3 and HClO4
a.) +1, +3 b.) -2, -1 c.) 0, -2 d.) +2, +4
12.) What are the bond angles in a tetrahedral shaped molecule?
a.) 120° b.) 180° c.) 104.5° d.) 109.5°
13.) What is the molecular shape around PF3?
a.) bent b.) tetrahedral c.) trigonal planar d.) trigonal pyramidal
14.) What are the electron domain geometry and the molecular geometry for PF6-?
a.) Octahedral, trigonal bipyramidal b.) sawhorse, octahedral
c.) Octahedral, octahedral d.) T-shaped, trigonal bipyramidal
15.) In the organic molecule, H
O=C-O-CH3
What is the bond angle around the first carbon between oxygen and hydrogen?
a.) 107.5° b.) 120° c.) 180° d.) 105.5°
16.) Which of the following molecules has sp2 hybridization?
a.) AlCl4- b.) BCl3 c.) CS2 d.) TeCl2
17.) If the hybridization around the central atom is (s) (p) (p) (p), what is the bond angle around the central atom?
- 120° b. 109.5° c. 90° d. 180°
18.) In the following problems, write out the chemical equation for the process described.
- Show the equation for the third ionization energy for Al.
- Show an equation for the electron affinity of Br.
19.) Draw the Lewis structure for CO32- include lone pairs.
- If there are resonance structures possible for this molecule, show them here.
- Draw all of the possible Lewis structure for the molecule BrFCO, and write out the formal charges for all the structures to state which is the best structure.
20.) Draw an energy diagram for the bonding of two O- atomic orbitals to form the molecular orbital of O22-. Also state the whether the molecule is nonmagnetic, diamagnetic, or paramagnetic.
21.) Carbon dioxide has three resonance structures that can be drawn. Of the three resonance structures, the best structure is O == C == O. Comparing the bonds of this molecule to the bonds of CO32- what can you say about the differences between the two molecules’ bond strengths and their bond lengths?
- What would be the bond order for CO2 and for CO32-.
- Draw the hybrid orbital and atomic orbital overlapping regions for carbon dioxide, showing which overlaps are sigma bonds and which are pi bonds.
Formula / Lewis Structure / # of Electron Domains / Draw 3-D structure showing molecular geometry / Identify the molecular geometry (lone electron pairs are transparent) / Estimate bond angles around central atom / Molecule is polar, non-polar, or ionic / Hybridization around central atom
CF2
(sample) / / 2 / / linear / 180° / nonpolar / (sp)(p)(p)
a) H3O+
b) IBr3
c) BrF5
d) CH4
22.