U1D7: Density and Thickness of
Aluminum Lab
Do Now: (Calculators needed!)
1. Measurement Lab due
2. Density Lab out for check
3. Check HW #3 answer sheet and green pen (6.5 min)
Today:
1. Rounding Check
2. Density Lab
3) Rounding Homework
1) ADDITION ( Choose any 3)
22.313
32.0059
32.0 MW
0.66242
0.66 g
0.0945
345.788
174.767
0.095 km
22.3 cm
346 mmol
174.8 cg
Problem
Unrounded Answer
Rounded Answer, with
units
16.55
16.6 mg
32.405
32.405 cL
32.3151
32.32 J
362.98
363 kg
1.00115
1.0012 km
959.99677
960 cg
22.95 mg – 6.4 mg =
33.728 cL – 1.323 cL =
32.32 J – 0.0049 J =
378.98 kg – 16 kg =
1.00345 km – 0.0023 km =
960 cg – 0.00323 cg =
Problem
Unrounded Answer
Rounded Answer, with units
199.6666667
_
3
200 g/cm
5.0063113
5.006 g/cm3
0.01
0.01 cal/g
0.8190082
0.819 g/km
7.1097694
7.11 g/mol
14.4
10 g/L
4792 g / 24 cm3 =
7139 g / 1426 cm3 =
3.00 cal / 300 g =
19.82 g / 24.2 km =
64.77 g / 9.11 mol =
144.0 g / 10 L
F) OK, here is a practical problem in which you will
combine all of your skills.
1) A ring, supposedly made of pure silver (Ag) has a
mass of 20.445 grams. When its volume is taken by
water displacement, it is found to have a volume of
1.95 mL. Calculate the density of the ring:
D = m/V
D = (20.445 g) / (1.95 mL)
D = 10.4846125 g/mL
D= 10.5 g/mL
2) Based on the actual density of silver (Ag) found
on Reference Table S, could this ring actually be
made out of silver? Briefly explain your answer:
Yes –
Ag has a listed density of 10.500 on Reference
Table S.
Density and Thickness of Aluminum
Lab
Objective: I will successfully use known properties of
Aluminum to determine the thickness of a sheet of
aluminum foil to the correct level of precision.
Pre-Lab:
Why are you determining the density of aluminum in
this lab?
How does the density of aluminum foil differ from the
density of an aluminum block? Explain your answer.
Once the density of aluminum is calculated,
what data will you need to determine the
thickness of the aluminum foil?
• Remember: D=m/V and V = L*W*H (H is
the thickness of the aluminum foil)
Knowing that D=m/V and V = L*W*H , how can
you rearrange the formulas to calculate the
thickness of the aluminum foil.
So….what do you need to know?
So procedures…
• Glassware is being used so…. goggles
• Levels of precision for out instruments??
Balance _________________
Grad cylinder: ____________
Ruler: ___________________
• Note: cm3 =mL of water at the same temperature
• Formula for average:
Ave= (D1 +D2)/2
• Water displacement method: demo
• Math: ESSR! Box your final answer!
Clean up
All aluminum blocks get dried and returned to
teacher.
Graduated cylinders, rulers and balances get
returned to side of lab.
Return to seat to work on lab.
Goggles are removed only upon teacher
announcement that room is clean