BioGT: Acids, Bases, and the pH Scale

Ionization of water molecules

• Polar covalent bonds hold water molecules together

  • Because of their polarity, these bonds are relatively weak

• Water molecules are constantly breaking into OH- and H+ ions

  • OH is negative because it took the electron from the H that broke off

• These ions will detach and re-attach at a mostly steady rate

pH

• Water is neutral on the pH scale

• pH refers to the concentration of H+ ions

• OH- ions counteract H+ ions

• More H+ ions = more acidic

• More OH- ions = more basic (akaline)

• Water pulls of H+ ions from acids with polar covalent bonds.

• Acids neutralize bases

  • Mixing the two will give water and a salt

• pH scale

  • Each step represents a 10x change

    • pH of 6 is 10 times more acidic than ph of 7

  • Values of 0-6 are acidic

  • Values of 8-14 are akaline

  • 7 is neutral