25.11

Question 1

MgS

Answer 1

this is ionic bond, which is 4 times stronger than NaCl

MgO is also ionic (big difference in electronegativities)

Question 2

orbital geometry versus shape

Answer 2

SHAPE does not include lone pairs

Question 3

sp3 has 4 hybrid orbitals

Answer 3

derived from 1 s orbital and three p orbitals

Question 4

sigma bond is the simplest bond; pi bonds are extra

Answer 4

“SIGMA = SINGLE”

“Pie is extra”

Question 5

draw lewis structure of N2

Answer 5

TRIPLE BOND

Question 6

branching / LDF

Answer 6

branching inhibits LDF by REDUCING SURFACE AREA

unbranched have MORE LDF, hence HIGHER BP, Higher viscosity, and LOWER VAPOR PRESSURE

LDF - weakest ATTRACTIVE force, common in unbranched alkanes

lower vapor pressure

Question 7

strength of dispersion (attractive) forces INCREASES with atomic size

Answer 7

I2 > Br2 > Cl2 > F2

Br2 is a liquid and I2 is a solid

F2 and Cl2 are gases

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Question 8

2-methylhexane has a higher boiling point than pentane because IT HAS MORE CARBONS

Answer 8

more carbons = higher BP

Question 9

H2O NH3 and HF (period 2, grounds V, VI, and VII) have very strong hydrogen bonding

Answer 9

remember: CO2 is non-polar

HF hydrogen bonds with CO2 (HF is polar)

H2S does not bond with HCl

Question 10

Dipole movement

Answer 10

DRAW to ensure no symmetry!

Question 11

Resonance structures

Answer 11

Oxygen in OH can have a partial positive charge

Question 12

Zeff

Answer 12

increases going right (protons increase, number of fill shells remains constant) - atomic radius decreases

larger zeff results in negative electron affinity

Zeff INCREASES going DOWN and RIGHT