CE 225 EXAM 1 UPDATED QUESTIONS AND CORRECT
ANSWERS
Question:
1. experimental error
Answer:
Every measurement has uncertainty known as ---
Question:
2. systematic/determinate and random/inde-terminate
Answer:
2 types of experimental error
Question:
3. Flaws in equipment or experimental design EX: wrongly calibrated or uncalibrated bal-ance, ph
meter, buret, etc Reproducible Can be positive or negative Can be detected or corrected affects
ACCURACY
Answer:
What causes systematic/determinate er-ror? Examples Characteristics
Question:
4. Analyzing a known sample Analyzing blank samples Using different analytical methods to
mea-sure same quantity
Answer:
Detections of systematic error
Question:
5. Occurs from uncontrollable variables in a measurement EX: noise from instrument, different
people reading scale, etc. Always present Equal chance of showing positive or nega-tive Cannot be
corrected Affects PRECISION
Answer:
What causes random/indeterminate er-ror? Examples Characteristics
Question:
6. Absolute uncertainty
Answer:
Margin of uncertainty associated with a measurement
Question:
7. relative uncertainty Multiply by 100
Answer:
Ratio of the magnitude of absolute un-certainty to magnitude of its associated measurement How to
find percent of relative uncertainty
Question:
8. absolute uncertainties (percent) relative uncertainties
ANSWERS
Question:
1. experimental error
Answer:
Every measurement has uncertainty known as ---
Question:
2. systematic/determinate and random/inde-terminate
Answer:
2 types of experimental error
Question:
3. Flaws in equipment or experimental design EX: wrongly calibrated or uncalibrated bal-ance, ph
meter, buret, etc Reproducible Can be positive or negative Can be detected or corrected affects
ACCURACY
Answer:
What causes systematic/determinate er-ror? Examples Characteristics
Question:
4. Analyzing a known sample Analyzing blank samples Using different analytical methods to
mea-sure same quantity
Answer:
Detections of systematic error
Question:
5. Occurs from uncontrollable variables in a measurement EX: noise from instrument, different
people reading scale, etc. Always present Equal chance of showing positive or nega-tive Cannot be
corrected Affects PRECISION
Answer:
What causes random/indeterminate er-ror? Examples Characteristics
Question:
6. Absolute uncertainty
Answer:
Margin of uncertainty associated with a measurement
Question:
7. relative uncertainty Multiply by 100
Answer:
Ratio of the magnitude of absolute un-certainty to magnitude of its associated measurement How to
find percent of relative uncertainty
Question:
8. absolute uncertainties (percent) relative uncertainties