Accuracy vs Precision
What is the definition of accuracy?
When the measurements are close to the accepted value.
What is the percent error formula?
(|exp - acc| / acc) x 100%
How many significant figures are in 1.00 lbs?
3 sig figs
In scientific notation, will very small numbers have a positive or negative exponent?
Negative exponent
Name and describe the purpose of 1 piece of lab safety equipment.
goggles, aprons, fire extinguisher, shower, eye wash station, close-toed shoes, etc.
What is the definition of precision?
When the measurements are close to each other.
Your experimental value is 2.02 m and the accepted value is 2.40 m. What is your percent error?
15.8%
How many sig figs are in 0.004030 m?
4 sig figs
What is the purpose of using scientific notation?
To easily write very large or very small numbers.
What is the most SEVERE signal word?
Danger
Are the following measurements precise, accurate, both, or neither, given that the accepted value is 30 cm: 30.2 cm, 28.7 cm, 34.0 cm, 29.9 cm.
Accurate
Your experimental value is 568.0 and the accepted value is 570. What is the percent error?
0.351%
Round 0.009801 cm to 3 sig figs
0.00980 cm
Write 2,348,000 in scientific notation.
2.348 x 106
What is the purpose of using an Erlenmeyer flask?
Swirling or mixing a solution
What would be the most precise way to measure 15 mL of water - a 25 mL graduated cylinder, a 10 mL volumetric pipet, a 25 mL beaker?
a 25 mL graduated cylinder
You complete three trials of an experiment and get the following measurements: 24.1 m, 24.4 m, and 25.0 m. What is the average percent error, given that the accepted value is 24.5 m?
0%
Complete the following calculation:
0.023 cm x 22.50 cm
0.52 cm2
Write 0.00804 in scientific notation.
8.04 x 10-3
How is the purpose of a graduated cylinder different than the purpose of a beaker?
A graduated cylinder is used to measure solutions, while a beaker is used to hold solutions.
Given that the accepted value is 75 mL, are the following measurements accurate, precise, both, or neither?
65.0 mL, 65.3 mL, 64.9 mL
Precise
You get a percent error of 2% and the accepted value is 29 cm. What was your experimental value?
29.58 cm
Complete the following calculation
2.00 ft + 78.1 ft + 0.0078 ft =
80.1 ft
Divide 2.05 x 10-3 by 3.33 x 10-5
61.6
Name 3 things found on a Safety Data Sheet.
Hazard statements, precautionary statements, signal words, NFPA diamonds, chemical and physical properties, etc.