Chapter 2 Lecture 3 - Properties of Water, Acids and Bases, pH, Measures of Concentration Flashcards
What percentage of the body is comprised of water?
50-75%
What percentage of the blood is comprised of water?
92%
Why is water so important?
Atoms are joined by polar-covalent bonds, molecules are v shape
Solvent
Dissolves a solute
Solute
Dissolved in the solvent
Is water a solvent or a solute
solvent
Why can substances dissolve in water
It is polar
How does water play a major role in chemical reactions
Ionizes acids and salts, as well as itself. These ions can then be used in other reactions
Acid
Proton donor, any substance that releases H+ ions
Base
Proton acceptor or any substance that binds to or accepts H+ or releases OH-. DOES NOT HAVE TO DONATE OH-
Buffer
Solution of acid base pairs in which acid and base components occur in similar concentrations
How to calculate pH
ph=-log[H+]
What is the molarity of H+ in water
1.0x10^-7
What is the difference in H+ concentration between any two values on the pH scale
10x
What is the normal pH of human blood
7.4
Function of buffers
resist changes in pH, convert strong (completely dissociated) acids or bases to weak, slightly dissociated ones
Carbonic acid - Bicarbonate system
H2O+CO2 Carbonic Acid (H2CO3) Biarbonate ion (HCO3-) + H+
Weight per volume
Weight of solute in given volume of solution
Ex. of weight per volume
serum cholesterol (200mg/dL)
Percentage (concentration)
weight of solute as % of volume of a solution (volume/volume)
Molarity
of moles of a chemical per liter of a solution
Milliquivalents per liter
used to express electrolyte concentration. Takes into account mM concentrations as well as charge
