Lab 2E

Objectives: To calculate the thickness of a sheet of aluminum foil and express the answer of proper scientific notation and significant figures.

Equipment

3 rectangular pieces of aluminum foil ( minimum 15 cm x 15 cm )

metric ruler

centigram balance

Procedure

Put the rectangular pieces of aluminum foil on each side and write number 1-3 on each respectively. Measure the length and width of each piece with a metric ruler. Record measurements ( using sig figs ) on table 1. Find the mass of each piece with a centigram balance and record it. Finally, compare and discuss results with groupmates.

 Sheet       Length ( cm )      Width ( cm )       Mass ( g )
   1               15.5                     14.6               0.88
   2               16.7                     15.1               1.05
   3               14.5                     14.9               1.02


The thickness of each foil   2.7 = density      ( D = M/V )
1 ) 2.7 = 0.88 / V                            2.38 = 15.5 x 14.6 x h
      V = 2.38 cm cubed                         h = 1.05 x 10^-2
2 ) 2.7 = 1.05 / V                            0.39 = 16.7 x 15.1 x h
      V = 0.39 cm cubed                         h = 1.55 x 10^-3
3 ) 2.7 = 1.02 / V                            0.38 = 14.5 x 14.9 x h
      V = 0.38                                         h = 1.8 x 10^-3

Average thickness : ( 1.05 x 10^-2 + 1.5 x 10^-3 + 1.8 x 10^-3) / 3
                            = 4.6 x 10^-3

Accepted value = 1.55 x 10^-3
                 * sheet 2 has the most accurate result.

Here is a QUIZ to help you further understand mass volume and density and how to apply them to questions.