Chemistry SPA

Topics: Density, Mathematics, Volume Pages: 3 (696 words) Published: October 29, 2013

Pre Lab:
Background:
The Density of a material may be determined by determining the mass and volume of a sample material and calculating the mass/volume ratio. An independent variable is the variable that is being manipulated or changed during the experiment. The dependent variable is the variable that is being measured. The independent variable for this experiment is the copper because you are only changing the amount of copper you use. The dependent variable is the density because we are measuring the density. In this experiment the density will be calculated from raw data and also determined graphically from a mass vs. volume graph. Purpose:

Students will apply the scientific method in a lab setting, learn how to use the equipment correctly, and perform labs safely. Students will also use significant digits in measurement and calculations. Hypothesis:

If the mass and volume of a substance increase, then the density will increase as well. Materials:
Paper towels
Copper bb’s
Electronic balance
Pre-Lab Questions:
1) The density of copper is 8.92 g/mL.
2) The density of steel is 7.85 g/cm³
3) There is only one type of copper, so the density should be one specific density. However, there are multiple grades of steel, so the value of the density can vary. 4) If you determine the density by using a graphical method and the method of displacing the water in the beaker and weighing the mass on the scale, then the second method will be more accurate. Procedure:

1) Obtain multiple samples of metal. Record your sample group in the title of the data table. 2) Measure the mass of one sample. Record the Mass.
3) Fill a 100 mL graduated cylinder half full with water. Record the volume of the water. 4) Slowly pour the metal bb’s into the graduated cylinder half-filled with water. Record the volume of the water and metal. 5) Slowly pour the water out of the graduated cylinder with your hand over the top, being careful not to pour...