Substances, Mixtures, and Solubility - McGraw-Hill Higher Education

Groundwater dissolves
the limestone rock.
The solution of rock and
water drips in the cave.
When the water evaporates,
the limestone rock is left behind.
Figure 4 Orange and blue
lights illuminate this cave.
Stalactites and stalagmites
form when dissolved solids
crystallize and build up over
time.
Stalactites and
stalagmites form
as more rock
accumulates.
Stalactites and stalagmites in caves are
formed from solutions, as shown in Figure 4.
First, minerals dissolve in water as it flows through rocks at the top
of the cave. This solution of water and dissolved minerals drips
from the ceiling of the cave. When drops of the solution evaporate
from the roof of the cave, the minerals are left behind. They create
the hanging rock formations called stalactites. When drops of the
solution fall onto the floor of the cave and evaporate, they form stalagmites.
Very often, a stalactite develops downward while a stalagmite
develops upward
until the two meet. One
continuous column of
minerals is formed. This
process will be discussed
later.
Types of
Solutions
So far, you’ve learned
about types of solutions
in which a solid solute
dissolves in a liquid solvent.
But solutions can
be made up of different
combinations of solids,
liquids, and gases, as
shown in Table 2.
Table 2 Examples of Common Solutions
Solvent/ Solute/ State of
State State Solution
Earth’s nitrogen/gas oxygen/gas gas
atmosphere
carbon dioxide/gas
argon/gas
Ocean water water/liquid salt/solid liquid
oxygen/gas
carbon dioxide/gas
Carbonated water/liquid carbon dioxide/gas liquid
beverage
Brass copper/solid zinc/solid solid
SECTION 1 What is a solution 221