Percent Error and Density

1. Percent Error and Density

2. What does Percent Error Sound Like?

3. Measuring and calculating Percent Error tells us how well something was done. (ie how well you did your experiment….) Measured Value - Accepted Value X 100 = percent Error Accepted value

4. Lets Try This Together! Measured=40.35 g Calculated= 39.25g 40.35g -39.25g 39.25g = 0.02802 x 100 = 2.8%

5. Try on your own Measured: 25.55 g Calculated: 26.33g

6. What do you do when it’s Negative! Measured Value - Accepted Value X 100 = Present Error Accepted value 25.55g- 26.33g x100 = -2.962% 26.33 Take absolute Value of the answer = 2.962%

7. Ratio What are some examples of ratio’s?

8. Density • Mass: Volume Mass Volume D= M V

9. M D V

10. Unit Density = g/ml Mass = g Volume = ml or cm3

11. Lets try this Mass: 22.6g Volume: 25 ml What is the density?

12. Mass: 22.6g Volume: 25 ml 22.6g 25 ml = 0.90 g/ml Don’t Forget! 2 Sig Fig

13. On your own Density: 62 g/cm3 Mass: 12.33 g

14. 12.33g 62 g/cm3 0.19887 ~ 0.20 cm3 Division it gets flipped Unit Math: cm3 1 g cm3 1 g =

15. Density = 1.869g/cm3 • Volume = 23.6cm3

16. (1.869g/cm3)(23.6cm3) = 44.1084 ~ 44.1 g