Chem: Accuracy and Precision and Significant Figures
Introduction to Chemistry Laboratory:
A Lesson on Tools, Techniques and Measurements
PURPOSE: The purpose of this set of experiments (3 total) is to become familiar with the common types of laboratory glassware and equipment, and how to obtain and analyze data from these items.
LEARNING OBJECTIVES: By the end of this experiment, the student should be able to demonstrate the following proficiencies: 1. Know which glassware (beakers, burettes, pipettes, graduated cylinders, flasks, etc) should be used in various circumstances. 2. Know how to “correctly” measure volume and mass (weight).
3. Become familiar with significant figures and its relationship to measurements and data recording (significant figures). 4. Become familiar with the errors, precision and accuracy associated the various measurement tools and techniques.
5. Determine the density of liquids and solids.
6. Determine the best-fit straight line as a method to examine linear relationships and to use this relationship as a predicative model such as in the determination of the percent copper and zinc in pennies based on density measurements. 7. Record laboratory data and observations.
MATERIALS:
Erlenmeyer Flasks o 125 mL o 250 mL beakers o 100 mL graduated cylinders o 10 mL o 25mL
Burette
o 50 mL
Volumetric pipettes o 10 mL
Measuring pipet o 10 mL
Burette clamp and stand
Various liquids and solids for density determination measurements o Liquids
Distilled water
Heptane
Carbon Tetrachloride o Solids
Pennies
Copper
Zinc
Lead
Aluminum
BACKGROUND:
Laboratory glassware. There are two major categories of laboratory glassware:
(1) those that contain a certain volume (volumetric flasks) and
(2) those that deliver a certain volume (pipets, burets, and graduated cylinders).
“To Contain” glassware (sometimes labeled TC) is typically used for preparing solutions of known volume. “To
Deliver” glassware (sometimes labeled TD) is used to transfer known volumes between
A Lesson on Tools, Techniques and Measurements
PURPOSE: The purpose of this set of experiments (3 total) is to become familiar with the common types of laboratory glassware and equipment, and how to obtain and analyze data from these items.
LEARNING OBJECTIVES: By the end of this experiment, the student should be able to demonstrate the following proficiencies: 1. Know which glassware (beakers, burettes, pipettes, graduated cylinders, flasks, etc) should be used in various circumstances. 2. Know how to “correctly” measure volume and mass (weight).
3. Become familiar with significant figures and its relationship to measurements and data recording (significant figures). 4. Become familiar with the errors, precision and accuracy associated the various measurement tools and techniques.
5. Determine the density of liquids and solids.
6. Determine the best-fit straight line as a method to examine linear relationships and to use this relationship as a predicative model such as in the determination of the percent copper and zinc in pennies based on density measurements. 7. Record laboratory data and observations.
MATERIALS:
Erlenmeyer Flasks o 125 mL o 250 mL beakers o 100 mL graduated cylinders o 10 mL o 25mL
Burette
o 50 mL
Volumetric pipettes o 10 mL
Measuring pipet o 10 mL
Burette clamp and stand
Various liquids and solids for density determination measurements o Liquids
Distilled water
Heptane
Carbon Tetrachloride o Solids
Pennies
Copper
Zinc
Lead
Aluminum
BACKGROUND:
Laboratory glassware. There are two major categories of laboratory glassware:
(1) those that contain a certain volume (volumetric flasks) and
(2) those that deliver a certain volume (pipets, burets, and graduated cylinders).
“To Contain” glassware (sometimes labeled TC) is typically used for preparing solutions of known volume. “To
Deliver” glassware (sometimes labeled TD) is used to transfer known volumes between