chemistry unit 6

pure substance

made of one type of element or compound

element

made of one type of atom

compound

two or more atoms chemically bonded

mixture

combination of pure substances

homogeneous mixture

mixture with uniform composition

heterogeneous mixture

mixture with varied composition

solution

homogeneous mixture of two or more substances

solvent

substance that dissolves the solute

solute

substance that gets dissolved

alloy

homogeneous mixture of metals

suspension

heterogeneous mixture with large particles that settle

colloid

heterogeneous mixture with small particles that don’t settle

brownian motion

constant, random motion of particles

tyndall effect

light scattering in colloids and some suspensions

distillation

separates using boiling points

crystallization

separates by evaporating solvent

chromatography

separates by particle size or density

centrifuge

separates by spinning based on density

long standing

separation by letting mixture sit over time

neutralization

acid + base → salt + water

salt

product of an acid-base reaction

net ionic equation

shows only ions involved in the reaction

total ionic equation

shows all ions present

spectator ion

ion that doesn’t change in a reaction

strong acid

acid that dissociates completely in water

weak acid

acid that partially dissociates in water

strong base

base that dissociates completely in water

weak base

base that partially dissociates in water

electrolyte

forms ions in solution and conducts electricity

nonelectrolyte

doesn’t form ions and doesn’t conduct electricity

hydrolysis

dissociation of a salt in water

conductivity

ability to carry electricity or heat

pH

measures acidity; pH =

pOH

measures basicity; pOH =

acidic

pH less than 7

neutral

pH equals 7

basic

pH greater than 7

[H+][OH

]=10^

pH + pOH=14

relationship between pH and pOH

[H+]=10^

pH

[OH

]=10^

acidity

degree of acid strength

alkalinity

degree of base strength

acid

increases H+ concentration

base

increases OH

acids

taste sour, turn blue litmus red, react with metals

bases

taste bitter, slippery, turn red litmus blue

acids + carbonates

form CO2, water, and salt

bases + metal salts

form insoluble metal hydroxides

bases + CO2

form carbonates

dissociation

ionic compound separates into ions

ionization

covalent compound forms ions in water

hydration

water surrounds ions to keep them dissolved

aqueous

solution where water is the solvent

precipitate

solid formed in a solution

double-displacement

ions switch between compounds

strong electrolyte

dissociates completely

weak electrolyte

partially dissociates

nonelectrolyte

does not dissociate

net ionic equation

shows only ions that change in reaction

solubility

how much solute dissolves in a solvent

dissolution rate

speed at which solute dissolves

unsaturated

less than max solute dissolved

saturated

max solute dissolved

supersaturated

more than max solute dissolved

solubility graph

shows solubility vs. temperature

temperature

increases solubility of solids, decreases for gases

pressure

increases gas solubility, little effect on solids/liquids

like dissolves like

polar dissolves polar, nonpolar dissolves nonpolar

stirring

increases rate of dissolution

surface area

increases rate of dissolution

heat

increases rate of dissolution