9.2 Solutions

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Solutions
- The Importance of Water
- Types of Solutions
- Solubility and Solubility Rules
- Molarity and Dilutions

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Types of Solutions

Solution

� a mixture of two or more substances that is

identical throughout

� can be physically separated

� composed of solutes and solvents

the substance in the smallest

amount and the one that dissolves

in the solvent

the substance in the larger

amount that dissolves the solute

Colloids (milk, fog, Jello) are considered solutions

Iced Tea Mix

(solute)

Water
(solvent)
Iced Tea
(solution)

Multiple Choice

This is the part of the solution that does the dissolving. 

• solute
• solvent 

Multiple Choice

This is the part of the solution that is dissolved. 

• solute
• solvent 

The solute breaks up into tiny particles that spread

evenly throughout the solvent. In a solution of
sugar water, sugar is the solute, and water is the
solvent.

SOLUTE

SOLVENT

​In an Aqueous Solution the solvent is always water

Multiple Choice

When one of the parts of the solution is water we call it _________. 

• aqua-man
• aqueous 

Solutes Change Solvents

� The amount of solute in a solution determines how

much the physical properties of the solvent are changed

� Examples:

Lowering the Freezing Point

The freezing point of a

liquid solvent

decreases when a solute is

dissolved in it.

Ex. Pure water freezes at 320F

(00C), but when salt is

dissolved in it, the freezing point is

lowered.

This is why people use salt to melt

ice.

Raising the Boiling Point

The boiling point of a

solution is higher

than the boiling point of the

solvent.

Ex. The boiling point of salt water is

higher than pure

water, this is why a solution can

remain a liquid at

a higher temperature than its pure

solvent.

​https://www.youtube.com/shorts/71b1WOjqDPA
Adding NaCl lowers freezing point of water

https://www.youtube.com/shorts/wU7m_zUzElk
Adding NaCl increases the boiling point of water

Multiple Choice

The freezing point of a solution is ____ the freezing point of the pure solvent.

• the same as
• lower than
• higher than

Multiple Choice

The boiling point of a solution is ______ the boiling point of the pure solvent.

• higher than
• the same as
• lower than

Are all solutions liquids?

NO! Many types of solutions are possible.

Here are a few examples.

Strong Electrolytes, Weak Electrolytes and Nonelectrolyte
Solutions

Electrolyte Solutions

• Electrolytes are compounds that dissolve by breaking into ions (charged particles) in solution and conduct electricity

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Multiple Choice

a solute whose water solution conducts electricity is called a(n)

• electrolyte
• nonelectrolyte

Electrolytes

� Conduct an electrical

current when they are in
aqueous state (dissolved
in water)

� The particles of the

electrolytes align in a
solution to allow
electrons to flow.

Strong and Weak Electrolyte Solutions

• Strong Electrolytes are compounds that completely dissociate in solution

  • Separating into charged particles called ions

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• Weak Electrolytes are compounds that partially dissociate in solution

  • Separating into charged particles called ions

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​Weak electrolytes conduct a smaller amount of electricity

Multiple Choice

Which of the following best describes a weak electrolyte?

• Solution where the solute completely dissociates

• Solution where the solute partially dissociates

• Solute that does not dissolve in a solvent

Multiple Choice

Which of the following best describes a strong electrolyte?

• Solution where the solute completely dissociates

• Solution where the solute partially dissociates

• Solution where the solute does not dissociate

Electrolyte Solutions

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• Salts

  • Ionic Compounds (metal and nonmetal)

    • NaCl

• Acids

  • A chemical that dissociates releasing hydrogen (H⁺) ions in water

    • HCL

• Bases

  • A chemical that dissociates releasing Hydroxide (OH^-) ions

    • NaOH

Multiple Choice

Which substance increases the number of hydroxide ions (OH-) in a solution?

• Acid

• Base

• Ionic compound

Multiple Choice

Which substance increases the number of hydrogen ions (H⁺) in a solution?

• Acid

• Base

• Ionic compound

Multiple Choice

Which substance separates into it's individual ions in a solution?

• Acid

• Base

• Salt

Nonelectrolyte Solutions

• Nonpolar Covalent Compounds

  • Do not dissociate (separate) into ions in solution

  • Do NOT conduct electricity in solution

  • Do not dissolve in water

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*Fuzzy Chem*
Polar covalent molecules can slightly conduct electrical charge in solution

Multiple Choice

Solutions in which electric currents cannot run through are said to be

• noncolloidal
• electrolytes
• nonelectrolytes
• conductors

Open Ended

Write three things you remember about types of solutions.