1. Biological and Chemical Solution Preparation
Bio Sciences: Chemicals
Biological and Chemical Solution Preparation
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2. Bellwork
One area the stockroom I audited could be improved would by? One area the stockroom I audited did well was?
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3. Objectives Explain what a solution is and its components
Explain what a mole is.
Preform solution calculations
Explain the two (2) methods for making a solution
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4. Terminology
Moles: A unit of measurement or 6.023x1023 somethings used in chemical substance quantity expressions Molar Mass: The number of grams in 1 mole Solution: A solution is a homogeneous mixture of two or more substances (solvent and solute). A solution may exist in any phase (solid, liquid, or gas). Solvent: The substance in a solution that does the dissolving. Water is the universal solvent but other solvent are commonly used in the lab. Solute: The substance that is dissolved in the solution Homogenous: Solution composed of only one phase Heterogeneous: Solution composed of more than one phase
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5. What is a Solution Solution:
A solution is a homogeneous mixture of two or more substances (solvent and solute). A solution may exist in any phase (solid, liquid, or gas).
Solutions are composed of at least two (2) components.
Solute:
The substance that is dissolved in the solution (usually what is measured out)
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6. What is a Solution cont. Solvent:
The substance in a solution that does the dissolving. Water is the universal solvent but other solvent are commonly used in the lab.
Many times isopropyl alcohol, methanol, acetone, and ethanol are used in high school labs as solvent.
In industry there are many organic solvents commonly used
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7. Types of Solutions Liquids: Gas: Solids:
The solution and its components are either dissolve, suspended, or in a liquid phase. Liquid solutions are what we will focus on.
Gas:
A mixture of various gases. Air is a good example.
Solids:
A mixture of various solids. Concrete is a good example
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8. Types of Solutions Cont.
Homogeneous solution: Solution composed of only one phase Heterogeneous solution: Solution composed of more than one phase
Which of these is a homogeneous solution?
1 or 2 1
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9. Units Important in Solution Preparation
Name these units with your partner and be prepared to share
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10. No not what's on your skin!
The Mole
No not what's on your skin!
Before you get scared, what is a dozen?
What is a ton?
A mole is just a number of something's as well. It is a very big number.
Mole:
A unit of measurement or 6.023x1023 somethings used in chemical substance quantity expressions 12
2 000
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11. The Mole cont.
Because molecules that make up biological and chemical solutions are so small in order for us to measure them we have to work with an extremely large amount of them. Rather than use really big number, the value of the mole was created. 1 mole = somethings When using chemicals molar mass is used. Molar Mass (MM): The number of grams in 1 mole
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12. In order to convert between mass and volume the density of a substance needs to be known. Many times this can be found on a stock chemical label.
Make sure units match up, usually the volume unit for solids is in cm3, but we will use ml
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13. What volume will 2.0g of NaCl occupy, if the density of NaCl is 2.165g/ml? First what is the formula for going from mass to volume, tell your neighbor.
0.924ml
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14. What volume will 4.5g of NaCl occupy, if the density of NaCl is 2.165g/ml?
2.08ml
What mass will 1.6ml of NaCl occupy, if the density of NaCl is 2.165g/ml?
3.46g
What volume will 0.5g of gel agarose powder occupy, if its density is 1.20g/ml?
0.417ml
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15. In order to make solutions of specific strengths, the number of moles must be known. Since we can easily measure mass and then convert to moles that is how moles are measured out. For this conversion the molar mass (MM) must be known. Many times the MM can be found on a stock chemical label.
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16. Lets practice converting from moles to grams. If a solution calls for 0.08moles of Iodine and the molar mass of 253.3g/mol, how much should you weigh out? What is the formula to convert form moles to grams?
20.26g
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17. How many moles are in 3.0g of TAE if the molar mass is 101.2g/mol?
0.0296mol
If you needed 0.025moles of EDTA what mass would you use if the molar mass is g/mol?
7.30g
If you needed moles of NaOH what mass would you use if the molar mass is 40g/mol?
0.48g
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18. Making Solutions: What Volumes to Make
Choosing the appropriate volume to make: You must consider the amount needed vs. ability to accurately make (measure out) the amount needed. Think-Pair-Share: What could limit how we measure out biological and chemicals?
Sensitivity of scales accuracy of pipets
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19. Solution Preparation Equipment
Here are some of the more common pieces of equipment you will use to make solutions
Volumetric Flasks
Graduated cylinder
Magnetic stir plate and bar
Milligram Scales
Pipets
Beakers
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20. Making Solutions: 1st Method
Using dry biologicals and chemicals. 1. Determine concentration and volume of solution needed. 2. Calculate amount of solute needed from solution specifications. 3. Weight out calculated amount in appropriate volumetric flask or on weight boat. 4. Add small amount of solvent (at 25˚C) to volumetric flask unit solute is dissolved 5. Fill with solvent drop-wise to graduated mark on volumetric flask, insure solution is at 25˚C.
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21. Making Solutions: 2st Method
Same procedures as first method, but solute is pre-dissolved in a beaker before being added to volumetric flask.
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22. Making Solutions: Cautions
Mixing order: Always add Acids or Bases to water. Never add water to Acids or Bases Try not to calculate the volume of solvent to be added, just the total volume of solution and the add solvent until that is reached
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23. Closure
Parking Lot Use a post-it note to place questions or concerns you have regarding todays lesson
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