Chem II Exam 1

Question 1

Potential Energy

Answer 1

Attractive forces draw particles together

Question 2

Kinetic Energy

Answer 2

Movement disperses particles

Question 3

Dynamic equilibrium

Answer 3

Molecs enter and exit a phase at the same rate

Question 4

Vapor pressure

Answer 4

Pressure exerted by vapor on a liquid. Increases until equilibrium, then stays constant

Question 5

Vapor pressure and temperature

Answer 5

Directly proportional

Question 6

Vapor pressure and intermolecular forces

Answer 6

Inversely proportional

Question 7

Boiling point

Answer 7

Temperature at which vapor pressure = external pressure

Question 8

Ion dipole forces

Answer 8

Ion and dipole attract (ie ionic compound dissolves in water)

Question 9

Dipole dipole forces

Answer 9

Attractive forces between opposite charged poles of 2 polar molecules

Question 10

Dipole movement

Answer 10

How polar the molecule is

Question 11

Hydrogen bond

Answer 11

Hydrogen atom covalently bonded to a small, highly electronegative atom with lone electron pairs (N, O, or F) attracts negatively charged molecules

Question 12

Induced dipole

Answer 12

Nearby electric field induces distortion in electron cloud, inducing temporary dipole movement in nonpolar molecules and enhancing dipole movement in pokar molecules

Question 13

Polarizability

Answer 13

Ease with which the electron cloud is distorted. Smaller molecules are less polarizable bc electrons are held tightly. Inc down group, dec across period

Question 14

Dispersion force

Answer 14

Random instantaneous dipole in one molec induces dipole in another

Question 15

Surface tension

Answer 15

Stronger forces, higher surface tension

Question 16

Viscosity

Answer 16

Resistance to flow. Intermolecular forces & molecular shape impede movement of molecules past each other, increasing viscosity

Question 17

Capillarity

Answer 17

Rising of liquid through a narrow space against gravity. Adhesion - holds molecs to surface. Cohesion - holds molecs together

Question 18

Substances with ___ intermolecular forces dissolve in each other

Answer 18

Similar; like dissolves like

Question 19

Rate of solvation influenced by

Answer 19

Temp, agitation, surface area

Question 20

Molarity equation

Answer 20

M = (n solute) / (L solution)

Question 21

Molality equation

Answer 21

m = (n solute) / (kg solvent)

Question 22

Mole fraction

Answer 22

X = (n solute) / (n solute + n solution)

Question 23

Colligative properties

Answer 23

Depend on number of solute particles

Question 24

Vant hoff factor

Answer 24

Takes into account the dissociation of strong electrolytes to predict effect on solution.
i = (measured value for electrolytic solution) / (expected value for nonelectrolytic solution)