Sodium chloride (NaCl) solution, especially at a 5 M concentration, is a commonly used stock solution for a variety of solutions. One example of sodium chloride use is to precipitate nucleic acids during their extractions. To download the 5 M sodium chloride recipe as a PDF then click here. The recipe below can be used to prepare a 100 mL 5 M sodium chloride solution. Store 5 M sodium chloride solution at room temperature (+15oC – +25oC). Sodium chloride is not classified as hazardous. However, always be sure to read the safety data sheet before use.
Lab experiments and types of research often require preparation of chemical solutions in their procedure. We look at preparation of these chemical solutions by weight (w/v) and by volume (v/v). The glossary below cites definitions to know when your work calls for making these and the most accurate molar solutions. To this we add information designed for understanding how to use the pH scale when measuring acidity or alkalinity of a solution. Glossary, basic terms to understand...
Solute - The substance which dissolves in a solution Solvent - The substance which dissolves another to form a solution. For example, in a sugar and water solution, water is the solvent; sugar is the solute. Solution - A mixture of two or more pure substances. In a solution one pure substance is dissolved in another pure substance homogenously. For example, in a sugar and water solution, the solution has the same concentration throughout, ie. it is homogenous. Mole - A fundamental unit of mass (like a "dozen" to a baker) used by chemists. This term refers to a large number of elementary particles (atoms, molecules, ions, electrons, etc) of any substance. 1 mole is 6.02 x 1023 molecules of that substance. (Avogadro's number).M Introduction to preparation of solutions.Many experiments involving chemicals call for their use in solution form. That is, two or more substances are mixed together in known quantities. This may involve weighing a precise amount of dry material or measuring a precise amount of liquid. Preparing solutions accurately will improve an experiment's safety and chances for success. Solution 1: Using percentage by weight (w/v)FormulaThe formula for weight percent (w/v) is: [Mass of solute (g) / Volume of solution (ml)] x 100 ExampleA 10% NaCl solution has ten grams of sodium chloride dissolved in 100 ml of solution. ProcedureWeigh 10g of sodium chloride. Pour it into a graduated cylinder or volumetric flask containing about 80ml of water. Once the sodium chloride has dissolved completely (swirl the flask gently if necessary), add water to bring the volume up to the final 100 ml. Caution: Do not simply measure 100ml of water and add 10g of sodium chloride. This will introduce error because adding the solid will change the final volume of the solution and throw off the final percentage. Solution 2: Using percentage by volume (v/v)When the solute is a liquid, it is sometimes convenient to express the solution concentration as a volume percent. FormulaThe formula for volume percent (v/v) is: [Volume of solute (ml) / Volume of solution (ml)] x 100 ExampleMake 1000ml of a 5% by volume solution of ethylene glycol in water. Procedure
First, express the percent of solute as a decimal: 5% = 0.05 Multiply this decimal by the total volume: 0.05 x 1000ml = 50ml (ethylene glycol needed). Subtract the volume of solute (ethylene glycol) from the total solution volume: 1000ml (total solution volume) - 50ml (ethylene glycol volume) = 950ml (water needed) Dissolve 50ml ethylene glycol in a little less than 950ml of water. Now bring final volume of solution up to 1000ml with the addition of more water. (This eliminates any error because the final volume of the solution may not equal the calculated sum of the individual components). So, 50ml ethylene glycol / 1000ml solution x100 = 5% (v/v) ethylene glycol solution. Solution 3: Molar SolutionsMolar solutions are the most useful in chemical reaction calculations because they directly relate the moles of solute to the volume of solution. FormulaThe formula for molarity (M) is: moles of solute / 1 liter of solution or gram-molecular masses of solute / 1 liter of solution. Examples
The molecular weight of a sodium chloride molecule (NaCl) is 58.44, so one gram-molecular mass (=1 mole) is 58.44 g. We know this by looking at the periodic table. The atomic mass (or weight) of Na is 22.99, the atomic mass of Cl is 35.45, so 22.99 + 35.45 = 58.44. If you dissolve 58.44g of NaCl in a final volume of 1 liter, you have made a 1M NaCl solution, a 1 molar solution. Procedure
To make molar NaCl solutions of other concentrations dilute the mass of salt to 1000ml of solution as follows: 0.1M NaCl solution requires 0.1 x 58.44 g of NaCl = 5.844g 0.5M NaCl solution requires 0.5 x 58.44 g of NaCl = 29.22g 2M NaCl solution requires 2.0 x 58.44 g of NaCl = 116.88g Charity T. need to dissolve in the solution? 1 Expert Answer Calculate the moles of Sodium chloride required to prepare a solution of molarity 4 and volume 0.5 liters that is 2 moles. Multiply the number of moles with the molar mass of Sodium chloride which is approximately 58.5 g/mo.'' Then your answer is 117 grams. Molarity = moles/liters Moles = Molarity X liters 2 moles of NaCl 58.5 grams NaCl 1 mole NaCl
Molar Solutions Many of the solutions you will use are described in terms of their molarity, so check that you are comforable with the concept by describing how you would make 500mL of a 0.05M NaCl solution.
From Lewis Lab Wiki Jump to navigationJump to searchDissolve 233.76g in 800ml H2O.
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From Lewis Lab Wiki Jump to navigationJump to searchYou do not have permission to edit this page, for the following reason: The action you have requested is limited to users in the group: Users. You can view and copy the source of this page. Dissolve 233.76g in 800ml H<sub>2</sub>O. #Bring volume to 1L. #Distribute into 10 bottles (100ml each). #Autoclave on liquid cycle. [[Category:Protocols]] [[Category:Student Worker Solutions]] [[Category:Lab Solutions]]Return to 4M NaCl. Page 3From Lewis Lab Wiki
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