This document provides a cheat sheet on key concepts regarding solutions in chemistry. It defines important solution terms like solute, solvent, saturated and supersaturated solutions, and concentration. It describes methods for calculating concentration as percentages by mass/volume and using molarity and molality. Factors that affect solubility like temperature, pressure and "like dissolves like" are summarized. Equations for dilution and using molarity in stoichiometric calculations involving solutions are presented. The formation of solutions and electrolyte solutions are briefly outlined. Colloids are defined as solutions that scatter light, exhibiting the Tyndall effect.

1. High School Chemistry - Core Concept Cheat Sheet
19: Solutions
Key Solution Terms
Concentrations of Solution
 Solution: Homogeneous mixture. The solution formation
involves the breaking and forming of intermolecular forces.
Solution = Solute + Solvent.
 Solute: Substance being dissolved (in smaller amount).
% by mass: % mass  mass solute  100
mass solution
The mass units must match!
 Solvent: Substance doing the dissolving (in larger
amount).
Solute vs Solvent Mnemonic: Dissolve solute into
solvent = “Police came, the thief hide the lute in the vent.”
% by volume: % volume  volume solute  100
 Unsaturated Solution: The solution can hold more solute
particles.
% mass/volume: % mass / volume 
mass solute
100
volume solution
The volume unit is mL.
 Saturated Solution: The solution is holding as many
solute particles as it can.
 Supersaturated Solution: The solution contains more
solute particles than it should be able to at that
temperature. A solution can become supersaturated by
raising the temperature, which allows more solute to
dissolve, and then lowering the temperature slowly back
down.
 Concentration: ratio of solute to solvent or solution.
 Concentrated: high ratio of solute to solvent.
 Solubility Curve: Graph showing the solubility of a solid at
various temperatures.
 Dilute: low ratio of solute to solvent.
 Dilution: adding solvent to create a more dilute solution.
 Electrolyte: compounds dissociate into ions when
dissolved in water. Allows solution to conduct electricity.
 Colloids: Solution with solute particles large enough to
exhibit the Tyndall Effect.
 Tyndall Effect: The light is visible and scattered as it
travels through the colloid.
Molarity (M): Molarity  moles solute
L solution
Molality (m): Molality  moles solute
kg solvent
Molarity vs Molality Mnemonic: MolaRity (moles over Liter
solution) and MolaLity (moles over kg solvent) = “Rose to
Lover and Loyal to King!”
Calculations with Concentrations
Dilution equation: M1V1 = M2V2
M1 = original molarity
V1 = original volume
M2 = new molarity
V2 = new volume
Volume units must match!
Solution Stoichiometry:
Use molarity to form the equality between moles and liters of
a solution.
Example: How many liters of 1.7M HCl are needed to react
with 2.5 g Mg?
2.5g Mg
Formation of Solutions
Steps for solution formation:
1. “Expand the solvent”—break intermolecular forces within
the solvent.
2. “Expand the solute”—break intermolecular forces within
the solute.
3. Form new intermolecular forces between solute &
solvent.

Steps 1 & 2 require energy. Step 3 releases energy.

If the energy put in is much greater than the energy
released, the solution will not form.
Factors Affecting Solubility
“Like Dissolves Like”

Molecules with “like” bond properties will form similar
intermolecular forces with each other as they did with
themselves. Therefore, the energy released will be
similar to the energy put in.
Pressure:

Gases dissolve more when there is a higher pressure of
the gas above the solution.
Temperature:

Gases dissolve more when the temperature of the
solution is lower.

Most solids dissolve more when the temperature of the
solution is higher.
How to Use This Cheat Sheet: These are the keys related to this
blank sheet of paper. Review it again before the exams.
RapidLearningCenter.com
volume solution
The volume units must match!
1 mole
Mg
24.31 g
Mg
2 mole
HCl
1 mole
Mg
1 L HCl
1.7 mole
HCl
= 0.12 L HCl
Electrolyte Solutions
To break up into electrolytes:

Leave polyatomic ions together.

Use subscripts that are not a part of a polyatomic ion as
coefficients.
Examples:
NaNO3  Na+ + NO3CaCl2  Ca2+ + 2 Cl-
Colloids
Colloids - Solutions with large enough particles to scatter light.
Tyndall effect:
For a solution:
For a colloid:
topic. Try to read through it carefully twice then recite it out on a
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