Unit 2 Flashcards
properties of matter
physical
chemical
physical properties
properties that don’t involve substances changing into another substance
color, odor, taste, feel, density, melting point, boiling point, temperature
Ex: boiling point, “hard”, conductivity, melts
chemical properties
properties that involve substances changing into another substance
chemical reaction
Ex: sugar ferments -> alcohol, platinum doesn’t react with oxygen @ room temp, copper sheets on statue of liberty have green coating
matter
has volume & mass
three states: solid, liquid, gas
volume
the amount of space that an object occupies
mass
the amount of matter than an object contains
solid
rigid
has fixed shape & volume
liquid
has definite volume but takes shape of container
gas
has no fixed volume/shape
takes shape & volume of container
chemical reaction
1+ substances r changed into other substances
physical change
involves a change in 1+ phsy prop’s, but no change in the fundamental componenents thtat make up the substance
most common = changes of state
changes of state
solid -> liquid = melting
liquid -> solid = freezing
liquid -> gas = evaporation
gas -> liquid = condensation
gas -> solid = sublimation (dry ice)
solid -> gas = deposition
chemical change
reaction
involves a change in the fundamental components of the substance
a given substance changes into a diff substance/substances
element
a substance that can’t be broken down into other substances by chemical methods
compound
a substance composed of a given combo of elements that can be broken down into those elements by chem methods
mixture
a combo of substances in varying proportions
Ex: salt water
homogeneous/heterogeneous
homogeneous mixture
solution
uniform composition
Ex: mixed salt water
heterogeneous mixture
non-uniform composition
Ex: choc chip cookie, sand & water
pure substance
will always have same composition
element/compound
organization of matter
separation of mixtures
physical changes
distillation
filtration
distillation
liquid -> gas -> liquid
Ex: salt water. solution heated to vaporize(boil) water. water vapor cooled so that condenses back to liquid state & liquid is collected. after all water vaporized from original sample, pure sodium chloride remains. physical changes.
separates liquids based on boiling point by condensing vapor
used to recover liquids
filtration
Ex: mixture of salt(sodium chloride) & sand. sand = not soluble in water. add water & dissolve salt. filter so that salt solution passes thru & sand remains on filter. water then evaporated from salt.
separates solids from liquids
used to recover solids or liquids
qualitative
based on observations such as appearance, odor, color
quantitative
based on measurements such as mass, volume, temperature
evaporation
separates solids from liquids
used to recover solids
distilled water
water that has been evaporated & condensed to remove impurities
reagent
a substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs
precipitate
the formation of a solid in a solution during a chemical reaction
percent recovery
new total mass
original total mass
mass percent of ____ in mixture
mass of recovered ___
total mass of recovered solids
x 100
NaOH
sodium hydroxide
HCl
hydrochloric acid
M
molarity
measrue of concentration (moles/liter)
