Chemistry I Honors
Accuracy & Precision Lab
Prelab:
1.
Define accuracy.
2.
Define precision.
3.
Create a dartboard that is precise but not accurate using 5 dots.
Procedure:
1.
Go to Explore Learning and open the “Measuring Volume” gizmo. Use the 250mL beaker and the 50mL graduated cylinder.
2.
Pour 45.0mL of water into the 250ml-beaker.
3.
Now pour the water from the 250ml-beaker into the graduated cylinder.
4. Record the amount of water in the graduated cylinder. Record to 1 decimal place. Use the magnifying glass to see meniscus clearly.
5. Pour the water into the sink.
6. Repeat 4 times.
Data:
Trial
1
2
3
Volume in graduated
cylinder (mL)
Calculations:
1.
Average your 5 volumes together. Keep 1 decimal place in your answer. Be sure to include a unit.
2.
If the correct volume was supposed to be 63.0mL, what is your percent error?
4
5
3.
Find the lowest and highest volume and subtract. Divide this answer by 2 to find the range. Record the average with the +/- value.
Analysis:
1.
Based on your percent error, discuss your accuracy. Use to specific values.
2.
Based on your +/- value, discuss your precision. Use to specific values.