EXAM 1 MARATHON

polarity

100

A Carbon - Hydrogen system is always _______.

nonpolar

200

Which molecule has a dipole moment greater than zero?

a. CH₃OH

b. CH₃

c. CH₃CH₂CH₃

d. CCl₄

CH₃OH

300

When drawing Lewis dot structures, the _____ electronegative atom is in the center.

least

400

Nonpolar molecules have a dipole moment ______ zero. Polar molecules have a dipole moment ____ zero.

equal to; not equal to 

500

Which two molecules are both nonpolar?

a. CO₂ & H₂O

b. H₂O & CCl₄

c. CCl₄ & NH₃

d. CO₂ & CCl₄

CO₂ & CCl₄

IMFs

100

Rank the strengths of IMFs from strongest to weakest.

ion-dipole > hydrogen bonding > dipole-dipole > LDF

200

Ammonia (NH₃) can form ____ hydrogen bonds and water (H₂O) can form ____ hydrogen bonds.

one (1); two (2)

300

Which molecule would you expect to have the lowest boiling point?

a. CH₃

b. CH₃CH₂

c. CH₃CH₂CH₃

d. CH₃CH₂CH₃CH₂

CH₃

400

All of the following can have a dipole moment greater than zero except:

a. CH₃CN

b. C₂H₅OH

c. C₂H₄O

d. C₂H₆

C₂H₆

500

As IMF increases, __________ decreases.

vapor pressure

phase changes

100

Name a phase change that has a negative delta H.

freezing, deposition, condensation

200

Name a phase change that has a positive delta H.

vaporization, fusion, sublimation

300

Normal boiling point occurs at _____ atm.

one (1)

400

Which phase changes involve breaking IMFs? Which phase changes involve forming IMFs?

breaking: vaporization, sublimation, fusion (melting)

forming: condensation, deposition, freezing

500

DAILY DOUBLE

Why does delta H vap require more energy than delta H fusion?

delta H vap requires more energy than delta H fusion because gas has no IMF, so all IMFs in liquids must be destroyed.

solutions

100

Which IMF is responsible for making a solution?

ion-dipole

200

When forming an ion-dipole (think A---B where A = H2O and B = NaCl), the reaction is ________ (endothermic/exothermic) and delta H is _____ (positive/negative).

exothermic; negative

300

When delta H soln is negative, the reaction is __________ (endothermic/exothermic). delta H solv-solv and H solu-solu are ________  (greater/less than) than delta H solv-solu.

exothermic; less than

400

When delta H soln is positive, the reaction is __________ (endothermic/exothermic). delta H solv-solv and H solu-solu are ________  (greater/less than) than delta H solv-solu.

endothermic; greater than

500

Why isn't oil and water considered a solution?

Oil and water are immiscible. They do not form a homogenous mixture.

misc.

100

The electronegativity trend increases from _____ to ____ and _____ to ____.  What is the most electronegative atom?

left to right; bottom to top; Fluorine (F)

200

Draw the Lewis dot structure for SO₂. Include dipole arrows and assign partial charges. Don't worry about resonance. Determine if the molecule is polar or nonpolar.

{answer on mini whiteboard}

300

The higher the lattice energy, the _____ (harder or easier) it is to dissolve/separate ions.

harder

400

The two conditions for low solubility are:

1. strong lattice

2. weak hydration energy

500

FINAL JEOPARDY (discuss with team to determine how many points you want to bid)

Which of the following should have the highest vapor pressure?

a. C₄H₁₀, boiling point: -1 C

b. CH₂Cl₂, boiling point: 39.6 C

c. CH₃CH₂OH, boiling point: 78.2 C

d. H₂O, boiling point: 100 C

C₄H₁₀