Qrtr 4 final

Electrolytes and Nonelectrolytes
An electrolyte 7 is a compound that conducts and electrical current when in an aqueous solution or
molten state. This requires ions that are mobile and able to carry charges through the liquid. For this
reason, all ions are electrolytes because they dissociate ions. Sports drinks like Gatorade have a lot
of electrolytes from elements like potassium and sodium and give the body energy. Likewise, a
nonelectrolyte 8 is a compound that does not conduct electricity. Things like sugar are nonelectrolytes.
Back to electrolytes, not all electrolytes conduct the same amount of energy. In a strong electrolyte 9
all or most of the solute exists as ions. On the contrary, a weak electrolyte 10 conducts poorly because
only a small part of the solute exists as ions. Back to the example of Gatorade, it gives you energy
because your body uses electrolytes to carry electoral impulses to other cells which are crucial to fluid
balance and nerve/muscle function.
Hydrates
The water contained in a crystal is called the water of hydration 11 or water of crystallization. A
compound that contains water of hydration is called a hydrate 12 . When crystals are heated above
100 Celsius, they lose this water. The forces holding water in hydrates are not very strong, so water is
easily lost and regained. On the contrary, a substance that does not contain water is anhydrous 13 .
Some substances like cobalt(II) chloride change color in the presence in the presence of water. For
this reason, substances such as cobalt(II) chloride can be used to test for the presence of water. If a
hydrate has a vapor pressure higher than that of water, it will easily lose water or effloresce 14.
Hydrated ionic compounds remove water from the air to form higher hydrates and are called
hygroscopic 15 . Calcium chloride for example, removes water from the air and creates a very dry
environment. These are also called desiccant 16 - substances that remove water from the air and
create dry environments. Similarly, there a compounds known as deliquisent 17 . They remove
sufficient water from the atmosphere and from solutions.
15.3 Heterogeneous Aqueous Systems
Suspensions
There are many mixtures of water that don’t dissolve
completely into the water. Suspensions are a great example
of this. In a suspension 18 , the particles do not dissolve, but
rather settle out and separate from the water. The sand and
mud you can observe at the bottoms of bodies of water are
suspended in the water and make it murky because the particles are much too large to be dissolved.
Colloids
In addition to this, a colloid 19 is another heterogeneous
mixture where the particles are dispersed. The particles can
be dispersed in solid, liquid, or gas mediums. The main
difference from solutions and suspensions is that the particles
in colloids are larger than those in solutions but smaller than
suspensions. They are often cloudy or milky in appearance.
A unique property of colloids is the Tyndall effect 20 in which
the dispersed particles in colloids scatters light and doesn’t
allow it to shine through. This is why even though milk is a liquid, you can’t shine light through it.
Colloids also scintillate because the dispersed particles move more erratically, and keeps them from
settling. This is called Brownian motion 21 . Lastly, an emulsion 22 is a colloidal dispersion of a liquid in a
liquid. An emulsifying agent is required for a stable emulsion. Vinaigrettes, for example, are
emulsions made of oil and water with vinegar as the emulsifier or emulsifying agent.