1. Solution Concentration- Units of Measurement
Biotechnology I

2. Review What is a homogeneous solution?
How is a homogenous solution different from heterogeneous solution?

3. Essential Question(s)
How is solution concentration defined?
What are common units used for making chemical solutions in a Biotechnology lab?
How are the different units of concentration calculated?

4. Solutions Recap
What are the components of a solution?
Solvent
Solute

5. Concentration
Concentration: The amount of substance in a defined space or volume
Defined space or volume
Amount of substance

6. Think-Pair-Share
Where might you find concentration units? Give two examples.
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class

7. Common Concentration Units: Percent (%)
Three types of Units:

8. Sample Problem What is the percent of the following solution?
3 g of NaOH is added to a total volume of 100 mL of water.
[Mass / Total volume] x 100 = 3%
What type of percent?
w/v

9. Sample Problem
How many grams of NaCl must you add to 250 mL of water to make a 15% (m/v) solution.
Must first convert percentage to decimal by dividing by 100
Multiply the decimal by the total volume
(0.15) x 250 mL =
37.5 g

10. Common Concentration Units- Molarity
Molarity (M) is mole (mol) of solute divided by liters (L) of solution
Molarity = Moles solute/Liter of solution
Recall what is a mole?
specific number of particles
How do you find moles when given grams?
Grams / Molar Mass (g/mole) = moles

11. Sample Problem
What is the molarity of a 100ml solution made from 3.0g of NaOH? The molar mass of NaOH is 40 g / mol

12. Sample Problem
How many grams of MgCl2 must be add to 500 mL of water to make a 0.25 M solution? The molar mass of MgCl2 is g / mole.

13. Common Concentration Units: Parts Per Million

14. Sample Problem
0.025 g of giberellic acid is added to 250 mL of water. The density of water is 1.0 g / mL. What is the concentration in ppm?

15. IAN Assignment Complete Solution Concentration Problems in your IAN
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