160 likes | 172 Views
Learn how to calculate the mass of substances using density and volume measurements. This chapter includes step-by-step examples with clear explanations and helpful tips. Join the Chemistry Help Center today!
E N D
Chapter 1 Examples Matter and Measurement
- To those whom much is given, much is expected. • John F. Kennedy
Chemistry Help Center • M-Th 7:30-9:30 • Keyes 104
Calculate the mass of 10.0 mL of CCl4(l). Given: d = 1.595 g cm-3
Calculate the mass of 10.0 mL of CH4 (l). Given: d = 1.595 g cm-3 w = 1.595 g/mL 10.0 mL w = 15.595 g w = d V
Always check units– helps to correct mistakes • Always give units • % and corresponding ratios are unitless: 15. g of sugar in 100. mL of coffee mass % = (15. g/100. g) 100% = 15. %
Find 12.56 – 11.2 Align the decimal points: 12.562 SFPDP 11.21 SFPDP 1.36 Final answer: 1.4 1 SFPDP
Find:2.765x10-3 43.2 2.765x10-3 4 SF x 43.23 SF 0.11945 Final answer: 0.119 3 SF
Find:(23.46 – 20.32)/12.34 Step-by-step: 23.47 – 20.32 = 3.15 2 SFPDP 3.15/12.34 = 0.25445 least precise: 3 SF Final answer: 0.254 3 SF
Keep at least one-extra SF in intermediate calculations Find: (12.65 1.65) – 11.4
Keep at least one-extra SF in intermediate calculations Find: (12.65 1.65) – 11.4 (12.65 1.65) = 20.87 20.87 – 11.4 = 9.47 Final answer: 9.5