slide1
Download
Skip this Video
Download Presentation
You think you know; but do you really know…

Loading in 2 Seconds...

play fullscreen
1 / 13

You think you know; but do you really know… - PowerPoint PPT Presentation


  • 58 Views
  • Uploaded on

You think you know; but do you really know…. 1. Are you familiar with the various types of intermolecular bonds? Y or N?. You think you know; but do you really know….

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' You think you know; but do you really know…' - guenevere-adams


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

You think you know; but do you really know…

1. Are you familiar with the various types of intermolecular bonds? Y or N?

slide2

You think you know; but do you really know…

2. Can you differentiate which would be the dominant force of attraction in various situations comparing molecules? Y or N?

slide3

You think you know; but do you really know…

3. What would the dominant force of attraction be in each of the following situations?

A. Two polar molecules with small and similar molar masses that do not contain hydrogen…

Dipole-Dipole

slide4

You think you know; but do you really know…

3. What would the dominant force of attraction be in each of the following situations?

B. Two polar molecules with small and similar molar masses; one containing hydrogen…

Dipole-Dipole and perhaps H-bonding!

slide5

You think you know; but do you really know …

3. What would the dominant force of attraction be in each of the following situations?

C. Two polar molecules with small and similar molar masses; one containing hydrogen bonded to nitrogen the other to chlorine. (note Cl and N have identical E.N.’s)

H-bonding!

slide6

You think you know; but do you really know …

3. What would the dominant force of attraction be in each of the following situations?

D. Two nonpolar molecules that may or may not contain hydrogen but definitely do not contain N, O or F.

LDF

slide7

You think you know; but do you really know …

4. Draw a 3-d Lewis Diagrams for dimethyl ether and ethyl alcohol. Then determine which has the highest boiling point.

dimethyl ether CH3OCH3

ethyl alcohol C2H5OH

Did you really know?????

slide8

# of particles

Particles with enough energy to break away

increases in number with higher temp.

K.E.

Threshold energyneeded for particles to breakaway

evaporation

=

rate

condensation

time

ln vp1 = (-DHv/R)(1/T1) + C

# of particles above the liquid is constant; vapor pressure can be measured.

ln vp2 = (-DHv/R)(1/T2) + C

vp

ln vp1 - (-DHv/R)(1/T1) = C

ln vp2 - (-DHv/R)(1/T2)

(higher at higher temp.s)

ln vp2 - (-DHv/R)(1/T2) = C

ln vp1 - ln vp2= (DHv/R)(1/T2) - (DHv/R)(1/T1)

temp

ln vp

ln vp = (-DHv/R)(1/T) + C

ln (vp1/vp2) = (DHv/R)(1/T2-1/T1)

The Clausius- Clapeyron Eq.

1 / T

slide9

Calculate the enthalpy of vaporization and the normal boiling point of methanol using the following data:

Calculate the enthalpy of vaporization and the normal boiling point of methanol using the following data:

Temp.(°C)V.P. (in mm Hg)

-6.0 20.0

5.0 40.0

12.1 60.0

21.2 100.0

slide10

Find DHv by manipulation of C-C equation:

DHv = ln(vp1/vp2) R

(1/T2 – 1/T1)

DHv = ln(40mm/60mm)8.31J/mol K

(1/285.1 K – 1/278 K)

DHv = -3.37J/mol K

(-8.96 x 10-5 K)

DHv = 37600 J/mol

DHv = 37.6 kJ/mol

slide11

Calculate the enthalpy of vaporization and the normal boiling point of methanol using the following data:

Calculate the enthalpy of vaporization and the normal boiling point of methanol using the following data:

Temp.(°C)V.P. (in mm Hg)

-6.0 20.0

5.0 40.0

12.1 60.0

21.2 100.0

slide12

Find B.P. by manipulation of C-C equation:

ln(vp1/vp2) R = (1/T2 – 1/T1)

DHv

ln(40mm/760mm)R = (1/T2 – 1/278.0 K)

37600 j/mol

(-0.0000783)R = (1/T2 – 1/278.0 K)

-0.000651 K = (1/T2 – 0.00360 K)

0.00295 K = 1/T2

339 K = T2

339 - 273 = 66° C = T2 = B.P.

slide13

Equilibrium Vapor Pressure Curve for Water

Boiling occurs when the vapor pressure of a liquid is equal to the atmospheric pressure.

…the boiling point is the temperature at which this occurs.

ad