BIOCHEMISTRY 2 2 PROPERTIES OF WATER Polarity Water

BIOCHEMISTRY 2 -2

PROPERTIES OF WATER Polarity- Water is polar because of the uneven distribution of electrons between the O and the H.

PROPERTIES OF WATER Hydrogen bond- Water molecules bond to other water molecules. A substance that is attracted (can bond) to itself is known as cohesion.

PROPERTIES OF WATER Adhesionattraction of molecules of different substances.

ASSIGNMENT • Make a water molecule!

THE *CHEMISTRY OF *WATER *Water is life… Key words: Polarity/Dipole, Cohesive, Adhesion, How does Water’s solubility break down a compound such as salt?

WATER OLYMPICS

Mixture- material composed of two or more elements or compounds that are physically mixed but not chemically combined.

Solution- liquid mixture Solute- the substance that is dissolved. Solvent –the substance into which the solute dissolves.

ACIDS, BASES AND PH • Acids- A solution that can donate a hydrogen ion- a proton to another substance. Have a higher H+ concentration. • Generally written in an equation as H(x) • Ex. HCl, HF, HBr • Acids are substances that have a p. H of less than 7. 0

ACID PROPERTIES • Taste- sour when dissolved in water- lemon, lime, grapefruit • Touch- acids produce a burning or stinging sensation.

ACID PROPERTIES • Reactivity- react aggressively with most metals. • Electrical Conductivity- can conduct a current depending on the strength of the acid. • Litmus paper- turns paper red

BASE PROPERTIES • A solution that can accept a hydrogen ion- a proton- from another substance. • A base is any solution that has a p. H greater than 7. 0

BASE PROPERTIES • Taste- bitter • Tough- slimy or soapy feeling.

BASE PROPERTIES • Reactivity- react violently with acids and can cause burning. • Electrical Conductivity- in solutions such as water will conduct electricity. • Litmus paper- turns paper blue

PH SCALE = POTENTIAL OF HYDROGEN • Identifies a substance as acidic or basic • 0 -6. 9 = acidic • 0 -4 strong acid • 4. 01 -6. 9 weak acid • 7. 01 -14= basic • 7. 01 -10= weak base • 10. 01 -14= strong base

BUFFER • Weak acids or bases that balance strong acids/bases in the body to help keep the body in homeostasis.

ASSIGNMENT