Water Molecule Packet

Book Notes ReviewPgs. 54-57

Polar Molecule: ◦ Molecule with a partial charge on opposite ends.

◦One end is slightly negative and the other end is slightly positive.

What makes a molecule polar?◦Shared electrons are attracted more strongly to one atom than the other.

Solubility:◦The ability of a polar molecule to attract opposite charges.

Give an example of something that can be dissolved by water:◦Sugar or salt

Give an example of something that cannot be dissolved by water:◦Oil, grease or wax

Hydrogen Bond:◦The attraction between two polar molecules

Most unique properties of water result because:Water molecules form hydrogen bonds with each

other.What causes Ice to float?

◦When water freezes into ice, empty spaces form between the water molecules making ice less dense than water.

Why does it take a long time for a large amount of water to change temperature?◦Hydrogen bonds are constantly breaking and

forming between water molecules causing water to absorb a lot of heat without changing temperature.

What is Cohesion?◦The attraction between particles of the same substance. (water attracted to water)

What is adhesion?◦The attraction between particles of different substances. (water attracted to a paper towel)

Solution:◦A mixture in which ions or molecules of one or more substances are evenly distributed in another substance.

Water dissolves many ionic and polar substances but does not dissolve nonpolar substances.

Sometimes, water molecules break apart to form ions.

What acid does your stomach use to digest food?◦HCl

What base is used to unclog drains?◦NaOH

pH:◦A measure of how acidic or basic a solution is.

Pure water has a pH of:◦7Lemon: AcidicMilk: Acidic/NeutralHand Soap: BasicVinegar: Acidic