Laboratory Techniques and Measurements

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Name: Kensley Shelley|Date: 9-17-12|
Exp 2: Laboratory Techniques & Measurements|Lab Section: 0000|

Data Tables:

Step 1: Length and Measurements

Object Measured|Length in cm|Length in mm|
Key|5.15 cm|51.5 mm|
CD|12.0 cm|120.0 mm|
Fork
Spoon|18.05 cm
16.30 cm|180.5 mm
163.0 mm|

Step 2: Warm Temperature Measurements

Hot tap water temperature49.50_˚C
Boiling water temperature __immediately:104.5; after 5 minutes: 103.0__˚C

Step 3: Cold Temperature Measurements

Cold tap water temperature_24.5_˚C
Ice water temperature after 1 min:4.5, after 5 min:1.0 ˚C

Step 4: Volume Measurements

Volume of half filled graduated cylinder__12.5__mL
Volume of completely filled small test tube __n/a__mL
Number of drops in 1 mL___14_drops
Volume of the micro pipet __28__ drops_2___mL

Step 6: Density Measurements
Part A
Mass of empty graduated cylinder_16.9_g
Mass of graduated cylinder and water 21.1_g
Net mass of the water __4.2_g
Density of the water_0.84_ g/mL

Part B
Mass of graduated cylinder and alcohol _20.4_g
Net mass of the alcohol __3.5_g
Density of the alcohol__0.7__ g/mL

Part C
Mass of graduated cylinder and salt solution ____g
Net mass of the salt solution____g
Density of the salt solution____ g/mL

Part D
Volume of half filled graduated cylinder__8.0__mL
Volume of half filled graduated cylinder and metal bolt_9.1__mL Volume of the metal bolt_1.1_mL
Mass of the metal bolt __7.2__g
Density of the metal bolt__6.55__g/mL

Part E
Mass of half filled beaker__89.0__g
Mass of water displaced by metal bolt__90.1__g
Volume of the metal bolt__1.1__cc
Density of the metal bolt__6.55__g/cc

Mass of half filled beaker__89.0__g
Mass of water displaced by magnet__89.8__g
Volume of the magnet _0.8_cc Mass of the magnet __4.0_g Mass when dropping the magnet in the beaker__92.9__g

Density of the magnet__5.00__g/cc

Calculated volume of the magnet using dimensions
of length x width x height__0.78__cc
Density of magnet using the calculated volume_5.13___g/cc

Conclusion:

Questions and Problems:

A. Which method of determining density is more accurate, the water displacement method in Part D or Archimedes’ principle method in Part E? Why? For the metal bolt, I received the same answer for both experiments, so I would say both were equally accurate in my experiment.

B. What is the relationship between mL and cm3?
They equal each other; mL = cc

C. Everyone knows that water is supposed to boil at 100° C. Why did your water sample boil at a different temperature? Water boils at different temperatures depending on the altitude. The higher pressure in the air keeps the molecules from escaping as easily.

D. To help you get a feel for metric measurements, you need to know the relative magnitude of a few basic measurements. For example: 1 mm = thickness of a dime, a penny weighs 2 ½ grams, and 20°C = normal room temperature. Determine the following:

1. What is the mass in kilograms (kg) of a person who weighs 143 lb? 64.86 kg
2. What weighs approximately 1 g?
dollar bill, paper clip
3. What is approximately 1 cm long, wide or thick?
fingernail is 1 cm wide
4. What weighs about 100 g?
20 nickels, 40 pennies
5. What weighs about 1000 g?
1 liter of water

Conclusion:

The experiment was designed to help acquaint the student with proper laboratory measurements and techniques. This was done by allowing the student to use the different lab tools in a variety of ways, such as: heating, measurements, volume, and density. In completing this lab, I am better aware of the different tools which will be used and how to properly use...
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