Chapter 7

- Chapter 7 -(c)(d)25.26% C, 74.74% Cl 1 mol C2:103 mol Cð25:26 g CÞ¼ 2:103 mol C¼ 1:000 mol C12:01 g C2:103 1 mol Cl2:103 mol Clð74:74 g ClÞ¼ 2:108 mol Cl¼ 1:002 mol Cl35:45 g Cl2:108The empirical formula is CCl. The empirical formula mass is 47.46 g.molar massempirical formula mass ¼ 284:8g47:46 g ¼ 6:000The molecular formula is six times that of the empirical formula.Molecular formula ¼ C 6 Cl 6 .11.25% C, 88.75% Cl 1 mol Cð11:25 g CÞ¼ 0:9367 mol C12:01 g C 1 mol Clð88:75 g ClÞ¼ 2:504 mol Cl35:45 g Cl0:9367 mol C0:93672:504 mol Cl0:9367¼ 1:000 mol C¼ 2:673 mol ClMultiplying each by 3 give the empirical formula C 3 Cl 8 . The empirical formula mass is 319.6.Since the molar mass is also 319.6 the molecular formula is C 3 Cl 8 .68. The conversion is: s ! min ! hr ! day ! yr6:022 10 23 s 1 min 1hr 1 day 1 year¼ 1:910 10 16 years60 s 60 min 24 hr 365 days69. The conversion is: g ! mol ! atom 1 mol Cu 6:022 10 23 atomsð2:5gCuÞ¼ 2:4 10 22 atoms Cu63:55 g Cu mol70. The conversion is: molecules ! mol ! g 1 trillion ¼ 10 12 1000: 10 12 1 mol 92:09 g C3 H 8 O 3molecules C 3 H 8 O 36:022 10 23 molecules mol C 3 H 8 O 3¼ 1:529 10 7 gC 3 H 8 O 371. 6:1 10 9 people 1 mol people6:022 10 23 ¼ 1:0 10 14 mol of peoplepeople-72-