Bonding Frq S Apchem

Bonding Frq’s APchem

I

1. Magnesium chloride is an ionic solid with strong electrostatic attractions between a +2 and a – 2 ion, silicon tetrachloride is composed of non polar molecules with weak dispersion forces as the primary IMF. Dispersion forces require much less energy to overcome than the coulombic attraction between ions.
2. Magnesium chloride and magnesium fluoride are both ionic solids with strong coulombic attractions between ions. The attraction in mgF is greater because the F- ion is smaller than the cl- ion and attraction increases as distance between charged particles decreases.
3. F2 and Br2 both contain single covalent bonds formed from the overlap of a p orbital. The bond in br2 is achieved with a 4 p orbital f2 with a 2p orbital. 4 p orbitals are at much greater distance from the nucleus so the bond is longer
4. F2 is a should be a smaller molecule since n is smaller than f, however N2 contains 1 sigma and 2 pi bonds which make the bond much smaller than the sigma bond of f2.

II

1. Ammonia is polar molecule with a negative end at the N and positive ends at the H’s and since N is small and highly electroneg. The molecule is polar enough for Ammonia to exhibit hydrogen bonding as its primary IMF while methane is a nonpolar substance with weak dispersion forces b/t molecules. It takes more energy to overcome the h bonds in ammonia than the dispersion forces in methane
2. Ethane and hexane are both non polar molecules with weak dispersion forces between molecules however hexane is a more polarizable molecule containing more electrons than ethane. The more electrons in a molecule the more momentary dipoles form so attractions are greater.
3. Si is a network solid with strong single covalent bonds throughout, Cl2 is composed of non polar molecules with weak dispersion forces. It takes far more energy to break a covalent bond than it does to overcome dispersion forces
4. MgO and NaF are both ionic solids with a strong coulombic attraction b/t the ions. However attraction increases as the charge of the ions increases. MgO has +2 and -2 which attract better than the +1 – 1 in NaF

III

B i propane is a non polar hydrocarbon with weak dispersion forces throughout the sample

Propanone is a weakly polar molecule with dipole dipole attractions that are stronger than the dispersion forces in propane. The stronger the attractive forces the more energy that needs to be added to vaporize a substance

Ii Propanone and propanol are both polar molecules however propanol is more polar due to the OH group at the end of the molecule. The OH group is also capable of Hydrogend bonding with other OH groups. Hydrogen bonds require more energy to overcome than the dipole dipole attractions of propanone.

IV

A) f2 and i2 both nonpolar

Both have weak dispersion forces

I2 more electrons = more momentary dipoles= more energy to overcome

B )Ionic solids

Both have strong attraction between ions

Both are +1 – 1, so smaller ions NaF have greater attraction than larger ones CsCl

C ) ICl4 - has 4 bonds 1 lone pair

BF4- has 4 bonds no lone pairs

D) ammonia hydrogen bonds with water H to O, pH3 is polar but not as polar so the attractions b/t water is less.

VI

C in so2 there is resonance, more than 1 structure is needed to portray the molecule, as a result the bond length in So2 is an average of single and double bonds making them all the same length