Biological and Chemical Solution Preparation Bio Sciences: Chemicals Biological and Chemical Solution Preparation Property of CTE Joint Venture

Bellwork One area the stockroom I audited could be improved would by? One area the stockroom I audited did well was? Property of CTE Joint Venture

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 Property of CTE Joint Venture

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 Property of CTE Joint Venture

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) Property of CTE Joint Venture

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 Property of CTE Joint Venture

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 Property of CTE Joint Venture

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 Property of CTE Joint Venture

Units Important in Solution Preparation   Name these units with your partner and be prepared to share Property of CTE Joint Venture

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 Property of CTE Joint Venture

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 = 602 300 000 000 000 000 000 somethings When using chemicals molar mass is used. Molar Mass (MM): The number of grams in 1 mole Property of CTE Joint Venture

  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 Property of CTE Joint Venture

  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 Property of CTE Joint Venture

  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 Property of CTE Joint Venture

  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.     Property of CTE Joint Venture

  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 Property of CTE Joint Venture

  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 292.1g/mol? 7.30g If you needed 0.012 moles of NaOH what mass would you use if the molar mass is 40g/mol? 0.48g Property of CTE Joint Venture

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 Property of CTE Joint Venture

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 Property of CTE Joint Venture

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. Property of CTE Joint Venture

Making Solutions: 2st Method Same procedures as first method, but solute is pre-dissolved in a beaker before being added to volumetric flask. Property of CTE Joint Venture

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 Property of CTE Joint Venture

Closure Parking Lot Use a post-it note to place questions or concerns you have regarding todays lesson Property of CTE Joint Venture