Teacher Notes


Teacher Notes
Publication No. 12387
Make Your Own Dilution CalculatorStudent Laboratory KitMaterials Included In Kit
Dilution Calculator envelopes, 15
Dilution Calculator Inserts, 15 Teacher’s Quick Dilution Reference Guide Additional Materials Required
(for each group)
Calculator Colored pencils, blue, green orange, purple and red Pen, black ink Scissors Tape Safety PrecautionsExercise caution when working with scissors as they are sharp. Always cut away from yourself and others. Please follow all classroom safety guidelines. Correlation to Next Generation Science Standards (NGSS)^{†}Science & Engineering PracticesDeveloping and using modelsUsing mathematics and computational thinking Disciplinary Core IdeasMSPS1.A: Structure and Properties of MatterHSPS1.A: Structure and Properties of Matter Crosscutting ConceptsPatternsScale, proportion, and quantity Performance ExpectationsMSPS15. Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved. Sample DataDilution of concentrated acetic acid, CH_{3}CO_{2}H, 17.4 M M_{1} = 17.4 Molar {12387_Data_Equation_5}
To make 1.0 liter of 3.0 M acetic acid
M_{1} = 17.4 Molar
{12387_Data_Equation_6}
To make 1.0 liter of 1.0 M acetic acid
M_{1} = 17.4 Molar {12387_Data_Equation_7}
To make 1.0 liter of 0.50 M acetic acid
M_{1} = 17.4 Molar {12387_Data_Equation_8}
To make 1.0 liter of 0.01 M acetic acid
M_{1} = 17.4 Molar {12387_Data_Equation_9}

Student Pages


Student PagesMake Your Own Dilution CalculatorIntroductionSolutions are an important part of chemistry. Sometimes space and storage requirements do not permit having every concentration of each solution. Learn how to dilute acid and base solutions to obtain the desired concentration. Concepts
BackgroundThe amount of solute that is dissolved in a given quantity of solvent is called the concentration of the solution. A dilute solution contains only a small amount of solute in a given amount of solution, while more concentrated solutions contain larger amounts of solute in a given amount of solution. Molarity is most commonly used to describe the concentration of a solution. The molarity, M, of a solution is defined as the number of moles of solute in one liter of solution (Equation 1). {12387_Background_Equation_1}
Experiments often require a solution that is more dilute than what is on hand in the stockroom. In this case, a more concentrated stock solution must be diluted to obtain the desired concentration. To carry out a dilution, the following equation is used.
{12387_Background_Equation_2}
In this equation, Molarity _{concentrated soln}, is the concentration of the stock solution, volume_{concentrated soln} is the volume of the stock solution required to prepare the dilute solution, Molarity_{dilute soln} is the concentration of the desired dilute solution, and volume_{dilute soln} is the volume of the dilute solution needed. The dilution equation is commonly written as Equation 3. The subscripts 1 and 2 refer to the concentrated and the dilute solutions, respectively.
{12387_Background_Equation_3}
For example, assume that a 0.80 M sodium chloride solution is in the stockroom, but for another experiment, 100 mL of a 0.20 M sodium chloride solution is needed. In performing a dilution calculation, M_{1}, M_{2} and V_{2} are generally known and Equation 3 is rearranged to solve for the unknown V_{1}. Substituting the known values for this example into Equation 4 allows us to solve for the volume of the stock solution required to prepare the dilute solution. Thus, diluting 25 mL of 0.80 M sodium chloride to a final volume of 100 mL will result in a 0.20 M solution.
{12387_Background_Equation_4}
Proper analytical technique for preparing the diluted solution requires that the initial and final volumes (V_{1} and V_{2}) must be accurately measured using a graduated cylinder or, preferably, a pipet and a volumetric flask.
Materials
Calculator
Colored pencis, blue, green, orange, purple and red Dilution Calculator envelope Dilution Calculator Insert Pen, black ink Scissors Tape Safety PrecautionsExercise caution when working with scissors. Always cut away from yourself and others. Please follow all classroom safety guidelines. Procedure
