Chapter 8 + 9

Pure Substance

a matter with distinct properties and composition

Elements and Compounds

the 2 types of pure substances

Mixture

contains two or more substances not chemically combined

What are the two types of mixtures?

homogenous and heterogenous

Homogenous Mixture (Solution)

have uniform properties and composition

Solute

the substance present in the smaller amount

Solvent

the substance present in the larger amount

Aqueous Solutions

water is the solvent

Solution

transparent; homogenous mixtures with dissolved particles

Particle Diameter of a Solution

0.01 nm < 1 nm

Colloid

homogenous mixtures with suspended solid particles; not transparent

Particle Diameter of a Colloid

1 nm < 1000 nm

Suspensions

mixtures that contain solid particles that settle upon standing

Particle Diameter of Suspensions

1000 nm < particle diameter

Solubility

measure of how much solute will dissolve in a given amount of solvent at a given temperature

Saturated Solution

a solution whose concentration = the solubility limit for a given temperature

Unsaturated Solution

a solution whose concentration is below the solubility limit for a given temperature

Supersaturated Solution

a solution whose concentration is above the solubility limit for a given temperature

Equilibrium

the rate of forward reaction is equal to the rate of reverse reaction

Relationship Between Solubility of Solids Dissolved in Water and Temperature

direct relationship

Relationship Between Solubility of Gas Dissolved in Water and Temperature

indirect relationship

Strong Electrolytes

ionic compounds that dissolve in water and conduct electricity (completely ionize)

Weak Electrolytes

covalent compounds that partially ionize in water (do not completely ionize) and conduct electricity poorly

Non-electrolytes

soluble covalent compounds that do not ionize and do not conduct electricity

Unit in Which the Amount of a Dissolved Ion Found in Fluids Can Be Expressed

equivalent (Eq)

Concentration

the amount of a solute dissolved in a solution

How Concentration can be Expressed

Molarity

Isotonic System

salt concentration is the same on both sides of a semipermeable membrane

Osmosis

the passage of water through a semipermeable membrane

Osmotic Pressure

the pressure exerted on the membrane as water passes through it

Hypotonic Solution

the cell has higher concentration

Hypertonic Solution

the cell has a lower concentration

Diffusion

the movement of molecules in a direction that equalizes concentration

Dialysis

type of diffusion; small molecules (waste) diffuse out of the blood and move into the urine

Passive Transport

requires no energy or protein channel; only small molecules with no charges can pass directly through

Facilitated Diffusion

requires no energy; does require integral membrane proteins

Active Transport

requires energy and integral membrane proteins; moving from low to high concentration

pH

the level of acidity in a solution

Buffers

work to maintain a neutral pH in our body

Bronsted-Lowry Acid/Base

compound from which a proton can be removed (donor) and a compound that can remove a proton (acceptor)

Strong Acids

completely dissociate in water, forming hydronium ions and anions

Weak Acids

acids that only partially dissociate in water

Strong Bases

dissociate completely in water

Weak Bases

bases that partially dissociate in water

Neutralization

the reaction of a strong acid and a strong base; produces water and salt

Antacids

neutralize stomach acid (HCl)

Equilibrium Constant

molar concentration of products over the molar concentration of reactants

pH value greater than 7 (OH- concentration is greater than H+ concentration

basic

pH value less than 7 (H+ concentration is greater than OH- concentration)

acidic

What is the K_a value?

the equilibrium constant for acids

What does “p” mean

take the negative log of a number

What is the relationship between pK_a and acidity?

the smaller the pK_a, the stronger the acid

deprotonated

H+ ion(s) are lost

protonated

H+ ions are added

When pH is below the pK_a…

mostly protonated

When pH is above the pK_a…

mostly deproponated

If the pH is lower than the pK_a, which ions are more present?

H₃O+/H+

What is the role of a buffer?

to keep a neutral pH when acids/bases are added

What are the 3 major buffering systems our cells use to maintain pH?

proteins, phosphate buffering system, and bicarbonate buffering system

What are proteins made up of?

amino acids

Where does the phosphate buffer system occur?

cytoplasm

When hyperventilating, is your blood pH more acidic or basic?

basic

When hypo ventilating, is your blood pH more acidic or basic?

acidic