Properties of Water

Polarity

Molecules having uneven distribution of charges

Universal solvent

Water - due to its polarity and ability to dissolve other polar molecules

Hydrogen bonds

the weak intermolecular bonds that form between the hydrogen atom of one water molecule and the oxygen atom of another water molecule.

Solvent

Does the dissolving

Solute

Substance being dissolved

Solution

Solvent +Solute=Solution. EVENLY DISTRIBUTED

Water as a Polar Molecule

the oxygen has a partial negative charge, the hydrogen has a partial positive charge

Buffer

compound that prevents sharp, sudden changes in pH

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances (water and another substance)

capillary action

tendency of water to rise in a thin tube against the force of gravity, and due of the cohesion and adhesion forces of attraction.

Surface Tension

An invisible film at the surface of water that allows objects to walk. This is caused by COHESION

high specific heat

The ability of water to resist changes in temperature. Water can absorb or release a tremendous amount of energy with little change in actual temperature.

Acid

any compound that forms hydrogen (H+) ions in solution (<7 on the pH scale) e.g. lemon juice

Base

a compound that produces hydroxide ions (OH-) in solution (>7 on the pH scale) e.g. laundry detergent

pH scale

scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution; a pH of 0 to 7 is acidic, a pH of 7 is neutral, and a pH of 7 to 14 is basic

Homeostasis

the process of maintaining the body chemical and thermal components in equilibrium. What hormone is responsible with maintaining the water homeostasis in human's body?

Expansion upon freezing

hydrogen bonds in ice are more "ordered and spaced out" making ice larger and LESS DENSE

H2O

Chemical formula for water; two hydrogen + one oxygen

nonpolar

Even distribution of charge (no partial charges on a molecule). Does not mix with water. e.g. vegetable oil

Meniscus

The curved upper surface of a liquid in a tube. Caused by ADHESION (water sticking to side of tube)

Covalent Bond

A chemical bond formed when two atoms SHARE electrons.

Bond that forms water?

Water is two hydrogens and one oxygen in COVALENT bonds sharing electrons

Why do hydrogen bonds exist in water?

Hydrogen bonds in water are possible because water is polar.

Why are hydrogen bonds important in water?

Hydrogen bonds explain water's unique properties of cohesion, adhesion, high specific heat, expansion when freezing, etc.

How does a water strider skate on top of water?

Cohesion --> Surface Tension

What properties of water are useful to life?

Expansion when freezing: insulates fish when lakes freeze in winter (ice at top of lake)

High specific heat: Water temp stays relatively stable since it requires a lot of energy to heat up (temp. not varying wildly for poor fish)

Cohesion/Adhesion: Work together to form capillary action, water travels up trees against gravity to get water to all parts of trees/plants/etc