Water

Question 0

Water is a ______ molecule. (Explain)

Answer 0

Polar

Water is polar covalent
Water has slightly negative (oxygen) and slightly positive (hydrogen) sides.

Question 1

Four properties of water

Answer 1

1. Water resists change in temperature
2. Cohesion & adhesion
3. Water is a solvent
4. Ice is less dense than water

Question 2

Electronegativity

Answer 2

Atoms attraction for electrons shared in covalent bonds

More electronegativity = stronger pull on electrons & visa versa

In H2O hydrogen has less electronegativity, oxygen has more

Question 3

Hydrogen bonds

Answer 3

WEAK bond between 2 different polar MOLECULES

Positively charged H atoms bond with negatively charged O atoms of different H2O molecules

• bond constantly for extremely short periods of time

Question 4

Cohesion

Answer 4

Tendency of molecules to stick together

Hydrogen bonds are constantly forming keeping water stuck together
Water is unusually cohesive

Question 5

Surface tension

Answer 5

How difficult it is to stretch and break the surface of a liquid

H bonds give water a high surface tension, like a film

Question 6

Heat

Answer 6

Amount of energy associated with the movement of atoms and molecules in a body of matter

Question 7

Temperature

Answer 7

Intensity of the heat- average speed of molecules (not total amount of heat)

Question 8

Water resists change in temperature and evaporation

Answer 8

Water has a high boiling
When water cools- Bonds form and heat energy is released
When water heats- Hydrogen bonds break up and molecules speed up absorbing heat as it worms up