titration - Chemical Solutions and Acid-Base Titration...

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Chemical Solutions and Acid-Base Titration Objective: The purpose of this experiment is to gain experience in preparing solutions and to learn the technique of titration by using a buret to measure volume and an acid-base indicator to determine the titration's end point. The titration will be used to determine the concentration of an acid solution by titrating with a solution of base of known concentration. Safety Tips: Wear safety goggles at all times in the laboratory. HANDLE ALL SOLUTIONS WITH CAUTION. If acid and/or base is spilled on the counter top, clean it up immediately. IF A CHEMICAL IS SPILLED ON THE SKIN, IMMEDIATELY RINSE THE AREA WITH LARGE AMOUNTS OF WATER. Dispose of all solutions per instructor's directions. Sodium hydroxide, hydrochloric acid and sulfuric acid are corrosive and will damage clothing and skin. Wash skin immediately with large amounts of water if you come in contact with NaOH, HCl or H 2 SO 4 . Background: Chemical Solutions A solution is a homogeneous mixture of two or more substances. A solution is composed of a solute and a solvent. A solute is the chemical substance that is being dissolved and generally the substance that is present in the smaller amount. The solvent is the chemical substance that is doing the dissolving and generally the substance that is present in the greater amount. In many solutions, including body fluids and the oceans, water is the solvent. Water is considered the universal solvent. However, the solutes and solvents that make up solutions may be solids, liquids, or gases. Carbonated beverages are solutions of CO 2 gas in water. In some solutions, the distinction between solute and solvent is not certain. A solution that is 50% alcohol and 50% water is an example of such a solution. Since it is hard to determine which substance is dissolved in the other and both are present in the same amount, the distinction between the solute and the solvent is uncertain. A solution forms when the attractive forces between the solute and the solvent are similar. Not all substances will form solutions with each other. A polar (or ionic) solute such as sodium chloride (NaCl) is soluble in water, a polar solvent. As the NaCl dissolves, its ions separate into hydrated Na + and Cl - ions. The positive Na + ions are attracted to the partially negative oxygen atoms of water. At the same time, the negative Cl - ions are pulled into the solvent by their attraction to the partially positive hydrogen atoms of water. Water surrounds each ion and the ions are considered "hydrated". Water, which is polar, dissolves polar solutes such as glucose, alcohols and ionic salts like NaCl. Nonpolar solvents such as turpentine are needed to dissolve a nonpolar solute such as grease or oil. On the other hand, oil and water do not mix because of their different polar characteristics. Although a simplification, the requirement of similar electrical attraction between solute and solvent is sometimes stated as "like dissolves like".
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You will use a volumetric flask to make your solutions. A volumetric flask is used as a container to
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titration - Chemical Solutions and Acid-Base Titration...

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