Density of Liquids and Solids

A. Instructor Demonstration Take down observations as each step is performed by the instructor Make sure to label each layer of liquid and where each solid ended up being suspended

B. Density of Water Weigh 125mL Erlenmeyer flask with stopper Half fill 150mL beaker with DI water – Pipet 10mL into 125mL flask Weigh the flask, water, and stopper (mass) Repeat Calculate the density of the water for each trial

C. Density of an Unknown Liquid Obtain 25mL of unknown liquid in 100mL beaker – RECORD THE UNKNOWN NUMBER Weigh a 125mL Erlenmeyer flask with stopper Rinse 10mL pipet with unknown liquid (discard into waste) Pipet 10mL of unknown into flask – Stopper and weigh Repeat Calculate density of the unknown liquid

D. Density of a Rubber Stopper Weigh dry #2 rubber stopper Fill 100mL graduated cylinder half full with water – Record the initial volume Tilt graduated cylinder and allow stopper to slide down the side into the water – Record final volume Calculate the volume caused by displacement Repeat Calculate the density of the rubber stopper

E. Density of an Unknown Solid Obtain an unknown solid Weigh the unknown solid (mass) Measure the length, width, and thickness of the unknown solid Calculate the volume Repeat

F. Thickness of Aluminum Foil Obtain a rectangular piece of aluminum foil Record length and width of the foil Fold the foil twice – Weigh – Record the mass Calculate the volume and thickness of the aluminum foil – d= 2.70 g/cm 3

Last Notes 1.Turn in one lab report for the group 2.Each individual should turn in post lab questions 3.Perform each experiment and take necessary data –Do calculations if you have time remaining after all sections of the lab have been performed