Chemistry 2202 Test Bonding

CHEMISTRY 2202 TEST BONDING

UNIT III: BONDING NAME______

PART I

PART I:

Select the best answer for each of the following . Place letter answer on blank BEFORE number

___1. How many valence electrons does an arsenic atom have?

A) 1 B) 3

C) 5 D) 7

___2. How many occupied valence orbitals does helium have?

A) one B) two

C) three D) four

___3. The shape around each carbon atom in CF4 is....

A) trigonal planar B) tetrahedral

C) linear D) v-shaped

___4. How many electrons are shared between 2 atoms in a triple covalent bond?

A) 2 B) 4

C) 6 D) 8

____5. Which of the following has a very low melting point ?

A) Diamond B) Iron

C) Sodium chloride D) methane

___6. Which of the following exhibits network covalent bonding?

A) SiC B) SiCl4

C) CO D) CO2

___7. Which of the following elements occurs naturally as a diatomic molecule with 3 covalent bonds?

A) hydrogen B) oxygen

C) bromine D) nitrogen

___8. If the difference in electronegativites between 2 elements of a compound is 2.0, what type of bonding would most likely be present in a such a substance?

A) ionic B) nonpolar covalent

C) polar covalent D) network covalent

___9. A temporary displacement or dispersion of electrons away from one atom towards another

atom occurs in…..

A) nonpolar substances B) polar substances

C) all molecular substances D) all ionic substances

___10. Which of the following substances would not be expected to be soluble in water?

A) CH3Cl B) MgBr2

C) I2 D) NH3

___11. Which of the following is a linear molecule?

A) H2O B) HCN

C) SiF4 D) NI3

___12. Which of the following would not shatter when hit by a hammer?

A) calcium chloride B) potassium

C) sodium oxide D) lead(II)iodide

___13. The most polar covalent bond is.....

A) S--Br B) Br--Cl

C) S--Cl D) Cl--Cl

___14. Which of the following is a tetrahedral molecule?

A) CO2 B) HCN

C) SiF4 D) NI3

___15. Which of the following statements is true concerning dipole-dipole forces?

A) They exist between all molecules

B) They exist between all polar molecules

C) They are intramolecular (within) forces, not intermolecular

(between) forces

D) They exist between all nonpolar molecules

___16. Which of the following would be expected to have all 3 types of intermolecular forces?

A) CH3F B) HCl

C) NH3 D) H2Se

___17. When C2H6, SiO2, CH3OH and BaF2 are listed in order of decreasing boiling points (highest first and lowest last), what would the correct order would be....

A) BaF2, SiO2, CH3OH, C2H6 B) C2H6, CH3OH, BaF2, SiO2

C) SiO2, BaF2, CH3OH, C2H6 D) SiO2, CH3OH, BaF2, C2H6

___18. An element in Group VII A has.....

A) 1 lone pair and 3 bonding electrons

B) 2 lone pairs and 2 bonding electrons

C) 1 lone pair and 2 bonding electrons

D) 3 lone pairs and 1 bonding electrons

______19.

___20. A mystery compound has an extremely high melting point, conducts electricity when dissolved in water, and is a clear-white crystalline solid. Which compound would it be?

(A) sugar

(B) snow

(D) table salt

PART II: Answer all questions in the space provided.

1. Using Lewis dot diagrams show the electron rearrangement that occurs when Calcium metal atoms react with fluorine atoms. (2)

2. For each of the following pairs of substances, predict which substance would have the higher boiling point. Give reasons for your choice. (6)

A) SiC or SrO2

B) HOF or CH3F

C) NCl3 or NF2Br

3. For each of the following, draw the Lewis diagram, the shape diagram, give the name of the shape around each central atom, and indicate whether the molecule is polar or nonpolar. (16)

Molecule / Lewis Diagram / Name of shape for each central atom / Shape Diagram / Polar or nonpolar
NH3
CHBr3
CCl4
H2O