Units of Concentration

Bio Sciences; Chemicals

Bellwork

What is a homogeneous solution?

A homogeneous solution has the same uniform appearance and composition throughout, specifically only one phase present.

Objectives

1. Recall the parts of a solution2. Explain what concentration means3. Give example of where concentration units are used4. List common concentration units used in a lab5. Differentiate between the various concentration units

TerminologyConcentration: The amount of substance in a defined space or volumePercent w/w: Grams of solute divided by ml of total solutionPercent w/v: Milliliters of solute divided by ml of total solutionPercent v/v: Grams of solute divided by grams of total solutionMolarity: Mole of solute divided by liters of solutionMolality: moles of solute divided by kilograms of solventNormality: Is a multiple of molarity or a gram equivalent weight of a solute per liter of solutionParts per Million: One milligram (mg) per liter of water or kilogram of something.Parts per Billion: One micro gram ( g) per liter of water or kilogram of something.

Solutions Recap

What are the components of a solution

Solvent

Solute

Concentration

Concentration: The amount of substance in a defined space or volume

Defined space or volumeAmount of

substance

Where Are Concentration Units

Where might you find concentration units; I need at least three (3) examples?

Common Concentration Units: Percent

Percent (%). The mass/ volume of one components divided by the total mass/ volumew/v: Grams of solute divided by ml of total solution

v/v: Milliliters of solute divided by ml of total solution

w/w: Grams of solute divided by grams of total solution

Common Concentration Units: Percent cont.

 

3.0%

Common Concentration Units: Molarity

 

Specific number of particles

 

Common Concentration Units: Molarity cont.

What is the molarity of a 100ml solution made from 3.0g of NaOH?

 

 

Common Concentration Units: Molality

 

 

 

Compare

What is a similarity and a difference between Molarity and Molality?

Normality (N): Is a multiple of molarity either 1, 2, 3, 4, 5, etc.

Or a gram equivalent weight of a solute per liter of solution

Take 1N HCl:1N means 1 molecule of H+ of Cl- per molecule of HCl

Take 2N H2SO4:

2N means 2 molecules of H+ per molecule of H2SO4

Common Concentration Units: Normality

 

Common Concentration Units: Parts Per Million and Billion

Closure

Letter or Note to a FriendWrite a letter or a note to a friend explaining the difference between three (3) types of the concentration units we learned in the lesson.