Matter and Measurements Flashcards
(32 cards)
three phases of matter
solid, liquid, gas
liquid
has a fixed volume but is not rigid in shape & volume
gas
has neither a fixed volume nor shape
solid
has a fixed shape & volume
element
a type of matter that cannot be broken down into two or more pure substances
what is the only metal that is a liquid at room temperature
mercury
what is a compound
a pure substance that contains more than one element
example of a compound:
water is a compound of hydrogen and oxygen
compounds have fixed _________________.
compositions
what does it mean to have a fixed composition?
a given compound always contains the same elements in the same percentages by mass
another example of a compound is table salt, which contains sodium and chlorine
(NA) is a shiny, reactive metal and (Cl) is a poisonous, greenish-yellow gas. When these two elements are combined, a profound change takes place (it’s table salt!)
electrolysis
involves passing an electric current through a compound, usually in the liquid state
mixtures
a mixture contains two or more substances combined in such a way that each substance retains its chemical identity
example of mixture:
When you shake copper sulfate with sand
(Figure 1.4), the two substances do not react with one another. In contrast, when
sodium is exposed to chlorine gas, a new compound, sodium chloride, is formed.
what are the two types of mixtures
homogeneous and heterogeneous
is solvent usually a liquid or a solid?
it is usually the liquid
what is a solute usually?
it can be a solid, liquid, or gas
homogeneous mixtures
(also known as uniform mixtures) are ones in which the composition is the same throughout
heterogeneous mixtures
(nonuniform mixtures) are those in which the composition varies throughout
what are some methods that can be used to separate components of a mixture from one another?
filtration, distillation, chromatography (GLC & GC)
what type of mixture are most rocks?
heterogeneous (in a piece of granite, several components can be seen and distinguished so the things are not evenly mixed around)
what is filtration used to separate?
a heterogeneous solid-liquid mixture
how does filtration work?
the mixture is passed through a barrier with fine pores, such as filter paper.
example of filtration:
Copper sulfate, which is water-soluble, can be separated from sand by shaking with water.