Explore BrainMass
Share

Polarity, bond dissociation energy of molecules

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

Detailed answers & explanations would be great. If hand written please do not write in cursive for I have trouble reading it.

1. Using Lewis (electron-dot) structures, explain why the ClF3 molecule is polar and the BF3 molecule is not polar.

2. For the following questions refer to the following diatomic species.
(A) Li2
(B) B2
(C) N2
(D) O2
(E) F2
a) Which has the largest bond-dissociation energy?
b) Which has a bond order of 2?
c) Which contains 1 stigma (s) and 2 pi (p) bonds?

3. On the basis of bonding principles, predict whether each of the following compounds exists. In each case explain your prediction.
a) NF5
b) AsF5

4. A mixture of 6gm of O2 (g) and 9gm CH4(g) is placed in a 15L vessel at 0 degreed Celsius. What is the partial pressure of each gas and what is the total pressure in the vessel?

5. Describe the intermolecular forces that must be overcome to convert these substances from a liquid to a gas.
a) SO2
b) CH3COOH
c) H2S

6. Amorphous Silica, SiO2, has a density of about 2.2gm/cc whereas the density of crystalline quartz is 2.65 gm/cc. Account for the differences in density.

7. What are face centered and body centered crystal lattice?

© BrainMass Inc. brainmass.com October 25, 2018, 8:21 am ad1c9bdddf
https://brainmass.com/chemistry/general-chemistry/polarity-bond-dissociation-energy-molecules-537057

Solution Preview

1. For ClF_3, the total number of electrons = 28. There are 3 ligands = 8 x 3 = 24 electrons. The remaining 4 electrons should be 2 lone pairs on the central atom. Hence the molecule should be T-shaped.

See attached

The dipoles of the F's aligned vertically opposite to each other will cancel leaving the dipole of the horizontal Cl-F bond intact. Hence there will be net residual dipole moment making the compound polar.

Similarly for BF_3, the Lewis structure can be drawn as being trigonal planar as there are a total of 24 electrons.

See attached

The net dipole of any two B-F bonds will be equally and opposite in strength to the other B-F bond. Hence the dipoles will cancel leaving no residual dipole moment and hence making the compound non-polar.

2. The number of bonds between each atom decides the strength of the bond. Triple bonds will be stronger than double bonds in general. Of all the species, only N_2 has a triple bond. Hence it will have the ...

Solution Summary

A number of problems based on atomic theory are solved.

$2.19
See Also This Related BrainMass Solution

physical chemistry

One problem that we will continue to face as the population of the earth steadily increases is fresh water. Even though there is an abundance of water on this planet, less than 5% of it can be used to sustain life. Therefore, new ways of purifying water are being developed. One of the best recent developments is using reverse osmosis. This process is being used to obtain fresh water from sea water by desalinization (salt removal). A membrane permeable to water but not to salt separates compartments containing sea water and fresh water. The normal flow of water, due to osmosis, from the fresh water to the sea water compartment is reversed by applying pressure to sea water campartment. For purposes of this problem, assume that the sea water is 3.0 weight percent NaCl. What is the minumum pressure (above atmospheric pressure) that must be supplied to cause reverse osmosis to occur at 25 degrees Celsius.

A dilute aqueous solution NaOH is heated to boiling. The boiling point of this solution is greater than 100.01 degrees Celsius at 760 torr. As som eof the water is boiled off, the boiling point of the resultant solution is checked again and it is found to be less than the previous boiling point (i. e., less than 100.01 degrees Celsius). Explain all these observations as fully as possible. Also, determine the original molal concentration of the NaOH. kb for water is 0.512 degrees Celsius/molal. The boiling point of the original solution is actually 100.01024 degrees Celsius at 760 torr.

Both potassium chloride (KCL) and potassium hydroxide (KOH) are very soluble in water. However, as one increases the temperature of the solution, KCL becomes more soluble and KOH becomes less soluble. Explain

The alkaline earth metal beryllium, Be, is very small and forms covalent compounds instead of ionic compounds. Knowing this, what type of solids would BeFCl and BeCl2 form and which would have the higher melting point? Please explain the answer.

View Full Posting Details