SG 07 Solutions
Name ____KEY________ Per. _________
We can divide most everyday matter that we encounter into two categories: pure substances and mixtures.
Substances are either elements or ___compounds___ (neutrinos/ compounds/ noble gases), which are when 2 or more
elements have bonded chemically. Mixtures are when 2 or more substances have physically blended together without a
chemical change occurring.
When a mixture is composed entirely of particles that are the size of individuals atoms, ions, or molecules it is
called a __homogeneous__ (homogeneous/ heterogeneous) mixture. When a mixture is composed of particles that are
larger, meaning clumps of atoms ions, or molecules, it is called a __heterogeneous__ (homogeneous/ heterogeneous)
mixture. Homogeneous mixtures include solutions, alloys, and mixtures of gases. Heterogeneous mixtures include
__colloids__ (suspensions/ colloids), which are somewhat stable and have medium-sized particles, and
__suspensions__ (suspensions/ colloids), which are more unstable and have larger-sized particles.
When 2 substances form a homogeneous mixture and the substance doing the dissolving is a liquid, together
they form a ___solution___ (solvent/ solute/ solution). The dissolving substance, which there is usually more of, is
called the ___solvent___ (solvent/ solute/ solution). The substance being dissolved, which there is usually less of, is
called the ___solute___ (solvent/ solute/ solution).
Concentration is a measure of how much of a substance is dissolved in another substance. A substance’s
solubility is the ___maximum___ (minimum/ maximum) amount of that substance that can be dissolved in a solvent.
Most solid solutes ___increase____ (increase/ decrease) their solubility in water with increasing temperature. Most
gaseous solutes ___decrease___ (increase/ decrease) their solubility in water with increasing temperature and
increasing pressure. A solute that can dissolve in a solvent is described as being ____soluble____ (soluble/ insoluble).
A solute that cannot dissolve in a solvent is described as being ___insoluble___ (soluble/ insoluble). The dissolving
process can be speeded up by stirring or using a solute with a ___large___ (large/ small) surface area, for example
using a powder instead of large chunks of the solute.
If a solution has reached its maximum concentration, aka solubility, it is __saturated__ (unsaturated/
saturated/ supersaturated). If a solution has not yet reached its solubility it is __unsaturated__ (unsaturated/ saturated/
supersaturated). If a solution has somehow exceeded its solubility it is _supersaturated_ (unsaturated/ saturated/
supersaturated). The __precipitate__ (precipitate / solvent) is the solid that appears at the bottom of a container
because too much has dissolved or a chemical reaction has occurred.
The basic rule for predicting solubility is “like dissolves ____like____ (dislike/ like/ different)”. What it
means is that polar substances are more likely to dissolve in ____polar____ (nonpolar/ polar) solvents and nonpolar
substances are more likely to dissolve in __nonpolar__ (nonpolar/ polar) solvents. Fats, oils, lipids, and gasoline are
all examples of __nonpolar__ (nonpolar/ polar) substances. Water, vinegar, and alcohol are all examples of
___polar___ (nonpolar/ polar) substances. In biology, vitamins A and D are examples of __nonpolar__ (nonpolar/
polar) substances because they can accumulate in the body’s fatty tissues. Vitamins C and E are examples of
__polar__ (nonpolar/ polar) substances because they are soluble in water and any excess will be flushed out of the
body with the urine.
Applications for solutions chemistry include using salt to melt ice on roads because the salt ___raises___
(raises/ lowers) the melting point of water and preventing radiator fluid from boiling out by ___lowering___ (raising/
lowing) the boiling point of water. These are called colligative properties. Acids and ionic compounds are sometimes
called ___electrolytes___ (colloids/ electrolytes) because when dissolved in water they conduct electricity.
Separations are utilized in chemistry to isolate and measure various substances in a mixture. _Centrifugation_
(Distillation/ Centrifugation/ Chromatography/ Filtration) spins a mixture at a very high speed and causes the heavier
material to settle on the bottom of a tube. ___Filtration___ (Distillation/ Centrifugation/ Chromatography/ Filtration)
collects solid precipitates or suspension solids on paper while dissolved solutes pass through a funnel with the solvent.
__Distillation__ (Distillation/ Centrifugation/ Chromatography/ Filtration) takes advantage of substances’ differing
intermolecular attractions. _Chromatography_ (Distillation/ Centrifugation/ Chromatography/ Filtration) takes
advantage of liquid substances’ differing boiling points by having the substance with the lowest boiling point boil off
first and then condensed and collected.
Circle all of the following units that can be used for measuring concentration.
grams (g)
% composition
milliliters (mL)
g solute/ L solvent
meters (m)
liters (L)
parts per billion (ppb)
kilopascals (kPa)
moles (mol)
Kelvin (K)
degrees Celsius (˚C)
g solute/100 g H2O
mol/L
kilograms (kg)
parts per million (ppm)
M1 × V1 = M2 × V2
Molarity (M) =
Molarity (M)
# moles solute
1 L solution
1) On a molecular level, describe the process of grains of solid table salt, sodium chloride (NaCl), dissolving into
water. As a solid, the sodium chloride is stuck in a crystal with alternating positive and negative charges. When it hits the
water, the water (with its slightly positive and negative ends) pulls away oppositely charged ions one at a time as the
molecules move randomly.
2) On a molecular level, describe how the ions from an electrolyte facilitate electricity, electrons travelling, through
normally nonconductive water. The negative electrons are able to hop from positive ion to positive ion, which are
dissolved in the water, as the move from the negative electrode to the positive electrode.
3) If 21 moles of KI are dissolved in a 7 L solution, then what is the molarity of the solution?
21 mol KI
7 L solution = 3 M KI solution
4) How many moles of NaCl are dissolved in 400 mL of a 0.4 M NaCl solution?
0.4 mol NaCl
x
400 mL = 0.400 L
=
1 L solution
0.4 L solution
0.16 = 1 x
x = 0.16 mol NaCl
Use the below graph for questions 5 – 7.
5) 10 grams of KClO3 are dissolved in 50 g of water at 50 ˚C.
Will the solution be unsaturated, saturated, or supersaturated?
1,000 = 50 x
10 g KClO3
x
=
50
50
50 g H2O
100 g H2O
= 20 g KClO3 / 100 g H2O
6) 15 grams of NH4Cl are dissolved in 20 g of water at 70 ˚C.
Will the solution be unsaturated, saturated, or supersaturated?
1,500 = 20 x
15 g NH4Cl
x
=
20
20
20 g H2O
100 g H2O
= 75 g NH4Cl / 100 g
7) 2 grams of KClO3 are dissolved inH10
2O g of water at 80 ˚C.
Will the solution be unsaturated, saturated, or supersaturated?
200 = 10 x
2 g KClO3
x
=
10 10
10 g H2O
100 g H2O
= 20 g KClO3 / 100 g H2O
8) 3 liters of a 6.0 M solution of potassium iodide (KI) is diluted with water until the new solution has a volume of 36
liters. What is the new molarity of the potassium iodide solution?
18 = 36 M2
M1 × V1 = M2 × V2
M2 = 0.5 M KI solution
36
36
(6.0) × (3) = M2 × (36)
9) 4 liters of a 6.0 M solution of sodium chloride (NaCl) is diluted with water until the new solution has a molarity of
0.12 M. What is the new volume of the sodium chloride solution?
24 = 0.12 V2
M1 × V1 = M2 × V2
V2 = 200 L
0.12 0.12
(6.0) × (4) = (0.12) × V2