<p>Chemistry Name : Worksheet : Significant figures (Obj. 31-33)-2 Date :</p><p>A. Determine the number of significant figures in each of the following numbers.</p><p>1. _____ 1 230 6. _____ 4 100 000</p><p>2. _____ 202 7. _____ 35.0 </p><p>3. _____ 0.0230 8. _____ 510</p><p>4. _____ 1 020 020 9. _____ 210 000</p><p>5. _____ 0.07000 10. _____ 0.0101</p><p>B. Round off the following numbers to the number of significant figures indicated in parentheses.</p><p>11. 3350.0 (4) ______14. 878 002 (3) ______</p><p>12. 10.9 (2) ______15. 8 888 (3) ______</p><p>13. 5.555 (2) ______16. 312.999 (4) ______</p><p>C. Addition and subtraction : Determine the sum or difference of the following and express the final answer with the correct number of significant figures.</p><p>17. ______25.25 + 5.55</p><p>18. ______42.000 - 1.99</p><p>19. ______85.555 + 7.545</p><p>20. ______3.3339 - 3.000</p><p>21. ______2.22 + 8.80</p><p>E. Multiplication and division : Determine the product or quotient of the following and express the final answer with the correct number of significant figures.</p><p>22. ______50.0/5.0</p><p>23. ______4.4 x 2.2</p><p>24. ______3.55 x 5.369</p><p>25. ______30.0/6.000</p><p>26. ______25.56 x 4.0</p><p>27. ______500.0/10.0</p><p>28. ______85.5 x 4.000 D. Density Problems - Show all work. M 29. The equation for density is : D  , rearrange this equation to solve for V and M. V</p><p>30. Which of the following are units for density (circle all correct).</p><p> a. g/L b. kg/m3 c. km/s d. cg/cL e. ft∙lb f.. lb/in2 g. lb/in3</p><p>31. What is the density of an object which has a mass of 22.4 g and a volume of 88.0 mL ?</p><p>32. Gold has a density of 19.3 g/cm3. A person wants to sell an object that he believes is pure gold. To see if it is pure gold he finds the mass (24.7g) and the volume (1.28 cm3). Is the object gold?</p><p>33. What is the mass of 18.0 mL (1 mL = 1cm3) of pure gold?</p><p>34. What is the volume of 15.5 kg of pure gold?</p><p>Selected answers : 4. 6 7. 3 11. 3.350 x 103 15. 8 890 18. 40.01 21. 11.02 24 19.1 27. 50.0 31. .255 g/mL 32 . 19.3 g/cm3 (yes, its gold) 33. 347 g 34. 803 cm3</p>