Can this be done in 2 hours? | Chemistry homework help

2) Prepare 3% (weight percentage) NaCl solu�on 100mL from the 1.0M solu�on in part 1. Calcula�ons: Experiment Procedure: 841201 Carolina’s Solution Preparation Manual

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When mixing and repackaging chemicals, label properly. ©2015 Carolina Biological Supply Company Printed in USA Carolina Biological Supply Company has created this reference manual to enable you to prepare solutions. Although many types of solutions may be purchased from Carolina Biological Supply Company, you may wish to prepare these solutions yourself. The procedures in this manual will allow you to make almost any solution that you may require in your laboratory. Keep this manual in a convenient location and refer to it often. Remember: Always follow appropriate lab safety procedures when mixing and storing chemicals. Chemical Grades In order of purity, from highest to lowest.

ACS

Highest quality; often equals or exceeds the latest purity standards set by the American Chemical Society (ACS). This is the only universally accepted standard. Chemicals are of the highest purity attainable. Reagent Purity is generally equal to ACS grade. This grade is suitable for analytical work and is more than adequate for general lab use. Lab An upper-level intermediate quality. Exact impurities may not be known; however, usually pure enough for most educational laboratories. Chemicals from Carolina are not suitable for use in food, cosmetic, or pharmacological applications. When a substance, called a solute, is dissolved in another substance, called the solvent, a solution is formed. A solution is a uniform distribution of solute in solvent. For example, vinegar is a solution of acetic acid (the solute) in water (the solvent). The amount of solute in a solvent is important and can be expressed in several different ways. Some common units of concentration will be discussed in this manual. When making a solution, one must first decide what degree of chemical purity is needed. Many types of chemicals are available in several grades of purity. Most of the chemicals listed in our catalog belong to one of the following three categories, in order from most pure to least pure.

ACS

Reagent Laboratory Choose the most appropriate grade based on need and cost. Laboratory- grade chemicals, due to their low cost and good chemical purity, find wide use in educational applications, such as teaching laboratories at both the secondary school and college levels. Use reagent-grade chemicals when conducting quantitative analyses. ACS-grade chemicals are certified to meet the stringent specifications for purity as set forth by the American Chemical Society Committee on Analytical Reagents. Carolina also offers a choice of packaging for a limited number of chemicals. Corrosive chemicals, such as concentrated acids, are normally packaged in glass bottles. For safety and convenience, our customers can order these chemicals packaged in plastic-coated safety bottles. A plastic- coated safety bottle will not shatter when dropped, which helps to contain the spill and simplify cleanup. Look at the item descriptions in the chemical section of the catalog for those chemicals available in plastic-coated safety bottles. For safety purposes, read a chemical’s label twice before use. Read the label first when you take the chemical off the shelf, and again before you remove any chemical from the bottle. When preparing solutions using concentrated chemicals, slowly add the more concentrated solution to the less concentrated one. The reverse procedure can cause the solution to boil and spatter. Solution Preparation 1. Molar solutions Molarity (M) means the number of moles of solute per liter of solution. To prepare a 1 M solution, slowly add 1 gram formula weight of compound to a clean 1-L volumetric flask half filled with distilled or deionized water. Allow the compound to dissolve completely, swirling the flask gently if necessary. Once the solute is completely dissolved and the solution is at room temperature, dilute to the mark with water. Invert the flask several times to mix. To make a 1 M solution of sodium hydroxide, slowly add 40 g sodium hydroxide to 500 mL distilled or deionized water in a 1000- mL volumetric flask. When all the solid is dissolved and the solution is at room temperature, dilute to the mark and invert the flask several times to mix. To make a 1 M solution acetic acid, dissolve 60.05 g acetic acid in 500 mL distilled or deionized water in a 1000-mL volumetric flask. Because acetic acid is a liquid, the acid may also be measured by volume. Divide the mass of acid by its density (1.049 g/mL) to determine the volume (57.24 mL). Use either 60.05 g or 57.24 mL acetic acid to make the solution. Swirl the flask gently to mix the solution. When the solution is at room temperature, dilute to the mark and invert the flask several times to mix.