12Nov2013 Chemistry Lab

This week we did lab 7.5 part 2 and lab 8.1
Lab 7.5 part 2, Determine the concentration of an unknown solution was a continuation of what we had done last week, last week we had made 6 test tubes filled with copper sulfate solutions ranging from 48% to 1.5% mass-to-volume percentage. This week we put a random amount of copper sulfate into the 1.5% test tube from last week and compared the color of the unknown solution to the other solutions to figure out the mass-to-volume percentage of the unknown solution.
Lab 8.1, Determine molar mass by boiling point elevation, in section 8 of the book we explore colligative properties of solutions. The first part of lab 8.1 was determining the boiling point of water under ambient pressure, we simply boiled a beaker of water and measured the temperature at which the temperature stabilized, this gave us the temperature at which water boiled at our elevation and air pressure. Part two of lab 8.1 was preparing molal solutions of sodium chloride and sucrose. We made 6 beakers of differing molalites, 6, 3 and 1.5 mol/kg each of sodium chloride and sucrose. Part three of lab 8.1 was determining the boiling points of sodium chloride and sucrose solutions. The procedure for part three was very similar to part one but using the solutions of sodium chloride and sucrose instead of water. Using the boiling poring elevation constant our solvents along with the van’t Hoff factor and molality will let us determine the formula weight of our solutions.
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