ch. 10 and 11

Question 1

how to tell if a molecule is polar

Answer 1

positive and negative end

Question 2

if a structure is linear

Answer 2

the two polar bonds cancel out making it a nonpolar molecule

Question 3

sp3 hydridization means

Answer 3

bent electron geometry, polar and doesnt cancel out

Question 4

intermolecular forces for a pure substance are

Answer 4

covalent and based on positive and negative charges attract- not a chemical bond

Question 5

dipole- dipole

Answer 5

polar molecules- about 1% as strong as a covalent bond

Question 6

hydrogen bonding

Answer 6

same as dipole but stronger. not a covalent bond but an intermolecular force

Question 7

requirement for hydrogen bonds

Answer 7

covalent bond between H, N,O or F

Question 8

unusually high boiling point for

Answer 8

H2O, HF, NH3- large intermolecular forces

Question 9

London dispersion forces

Answer 9

electrons slosh around- can induce temporary dipoles- nonpolar molecules, weak attraction forces

Question 10

do all molecules have london forces

Answer 10

yes- more electrons, more I.M forces

Question 11

polarizability

Answer 11

I.M forces increase with molar mass (# of electrons)

Question 12

super critical fluids

Answer 12

density of a liquid but fill container like a gas- acts as a solvent

Question 13

critical temp

Answer 13

temp above which the vapor cannot be compressed to a liquid

Question 14

what is the molality definition

Answer 14

moles SOLUTE/ kg SOLVENT

Question 15

molarity definition

Answer 15

moles SOLUTE/ L SOLUTION

Question 16

for solutions as the concentration of the solute goes up

Answer 16

the boiling point, and osmotic pressure go up, but the freezing point and vapor pressure go down

Question 17

colligative properties

Answer 17

dependent on concentration of solute- independent of the chemical properties of solute, depend on nature of solvent

Question 18

what is i

Answer 18

vant hoff factor- # of particles per solute- moles PARTICLES/ moles SOLUTE

Question 19

enthalpy of vaporization

Answer 19

change for liquid going to gas - Hvap

Question 20

enthalpy of fusion

Answer 20

change in H for solid going to liquid- Hfusion

Question 21

viscosity

Answer 21

how “thick” a liquid is- H2O has a high viscosity but not compared to honey. -resistance of a liquid to flow

Question 22

surface tension

Answer 22

why bugs can walk on water. resistance of a liquid to increases in surface area. droplets- attracted to itself.

Question 23

what temperature does water boil at

Answer 23

100 degrees F but 373 K

Question 24

H vap for water in the equation for 2 data points

Answer 24

40,670

Question 25

what must we recognize when trying to figure out the vant hoff factor

Answer 25

polyatomic ions- only count as 1

Question 26

for exo and endothermic what are the characteristics

Answer 26

endothermic is positive and exothermic is negative - H solution can be large or small, + or -

Question 27

polar solutes dissolve in

Answer 27

polar solvents

Question 28

between polar and nonpolar which one is water loving

Answer 28

polar molecules are hydrophillic and nonpolar is hydrophobic

Question 29

what is henrys law and its characteristics

Answer 29

c=K*P c=conc. of gas P=partial pressure. concentration of gas is directly proportional to the partial pressure of the gas

Question 30

miscible mean

Answer 30

100% soluble in water

Question 31

how to rank solubility in water

Answer 31

the longer the chain of carbon the more hydrophobic is it because of the nonpolar bonds

Question 32

if ionic it is always going to be more soluble in

Answer 32

water- universal solvent

Question 33

water solubility depends on

Answer 33

if there are hydrogen bonds, polar

Question 34

as conc. of a solute goes up

Answer 34

boiling point goes up
freezing point goes down
vapor pressure decreases
osmotic pressure increases