[6.4] hydrogen bonding

Question 1

where are hydrogen bonds found?

Answer 1

between molecules containing:
- an electronegative atom with a pair of lone electrons
- a hydrogen attached to an electronegative atom

Question 2

what are the 3 examples of molecules with hydrogen bonds?

Answer 2

oxygen, nitrogen, and fluorine
> H-O, H-N, H-F

Question 3

what is the shape of a hydrogen bond?

Answer 3

the shape around the hydrogen atom involved in the hydrogen bond is linear

Question 4

draw a hydrogen bond between two molecules of water and two molecules of ammonia

Answer 4

google it xoxo
- have correct δ charges
- have correct 3D representations
- label ———– hydrogen bond

Question 5

what are some anomalous properties of water

Answer 5

• solid water is less dense than liquid water
• relatively high surface tension and viscosity
• higher mp and bp than expected

Question 6

why is solid water less dense than liquid water?

Answer 6

• hydrogen bonds hold water molecules apart in an open lattice structure
• the water molecules in ice are further apart than in water
• solid ice is less dense than liquid water and floats

Question 7

why does water have a relatively high surface tension and viscosity and higher mp and bp than expected?

Answer 7

due to strong hydrogen bonding