Laboratory Techniques and Measurements
Purpose: To gain practice working with lab equipment, and taking measurements such as mass, temperature, length mass in the laboratory. Practice converting found measurements into different units, such as obtaining a temperature reading in Celsius and then converting it into Fahrenheit and Kelvin. As well as determining density, and how do dilute a solution.
Procedure:
1. Read the entire lab manual on laboratory techniques and measurements, being sure to fully understand the steps and procedures.
2. Make sure you have a clean and safe area to work, gather all the supplies listed in the materials section of the manual.
3. Beginning with the measurements, take a ruler and find the length in cm of a cd, key, spoon and fork. Once you obtain the measurements convert the units from cm to mm then from mm to m.
4. Next is temperature measurements, turn on your burner and set the stand over it, following the instructions gather your temperature readings in Celsius and convert them into Fahrenheit and Kelvin.
5. Mass measurements, estimate the mass of each object, then weigh the object and then convert the weight from grams to kilograms.
6. Using the graduated cylinder, obtain the weight of it empty, measure out 5 ml of water (2nd time use isopropyl alcohol) and weigh it again, obtain the mass of the liquid, find the density and the percent error.
7. Take mass of the magnet along with length, width and height and using the data to find the volume and the density.
8. Using the graduated cylinder measure out close to 5ml of water recording your exact amount, place the magnet/bolt into the cylinder and record the final volume, using the data find the volume and density.
9. Fill the glass beacker ¾ of water place it on the scale and zero the scale, tie a string around the bolt/ magnet carefully without touching the sides of the beaker place the object into the water and obtain the mass of the displaced water, complete the calculations
10. Weigh out 8 grams of sugar, find the molecular weight moles in volumetric flask total volume and molarity.
11. Follow each step to dilute the concentration of water, using the volumetric flask and the equation m1 X v1= m2 X v2 to find the final concentration.
Observations and Data:
Object
Length (cm)
Length (mm)
Length (m)
Cd
11.9 cm
119 mm
0.119 m
Key
5.3 cm
53 mm
0.053 m
Spoon
15.5 cm
155 mm
0.155 m
Fork
17.9 cm
179 mm
0.179 m
To convert cm to mm I moved the decimal point 1 place to the right because centi is 10^-2 and mili is 10 ^-3. To convert millimeter to meters I moved the decimal place 3 places to the left.
Water
Temperature °C
Temperature °F
Temperature K
Hot from tap
45°C
113°F
318.15K
Boiling
90°C
194°F
363.15k
Boiling for 5 minutes
100°C
212°F
373.15K
Cold from tap
20°C
68°F
293.15K
Ice water-1 minute
2°c
35.6°F
275.15K
Ice water- 5 minutes
0°C
32°F
273.15k
When taking a temperature of a boiling liquid be sure not to touch the thermometer to the sides of the glass beaker. To convert Celsius to Fahrenheit I took degrees Celsius and times it by 1.8 and then added 32. To convert to Kalvin I took degrees Celsius and added 273.15.
Object
Estimated Mass (g)
Actual Mass (g)
Actual Mass (kg)
Pencil
10g
5.5g
0.0055kg
3 pennies
1g
7.5g
0.0075kg
1 quarter
2 g
5.7g
0.0057kg
2 quarters 3 dimes
5g
18.1g
0.0181kg
4 dimes, 5 pennies
5 g
21.4g
0.0214kg
3 quarters, 1 dime, 5 pennies
10g
31.7g
0.0317kg
Key
10g
10g
0.01kg
Key,1 quarter, 4 pennies
15 g
25.6g
0.0256kg I found I am not very good at estimating mass the only one I was spot on with was the mass of the key which was 10g. To convert grams to kilo grams I moved the decimal point 3 places to the left.
Liquid
Volume (ml)
Mass A Graduated cylinder (g)
Mass B Graduated cylinder with liquid (g)
Mass B-A
Liquid (g)
Density g/ml
%error
Water
5ml
16.5g
21.7
5.2
1.04
4%
Isopropyl alcohol
5ml
16.6g
21.0
4.4
0.88
11.9%
To find the density you take mass and divide it by volume. To obtain the percent error you
