Chapter 7

- Chapter 7 -(c) oxygen in 8.45 10 22 molecules SO 3The conversion is: molecules SO 3 ! mol SO 3 ! gO8:45 10 22 1 mol48:00 g Omolecules SO 36:022 10 23 ¼ 6:74 g Omolecules mol SO 320. The number of grams of:(a) chlorine in 5.00 g PbCl 2ð5:00 g PbCl 2 Þ70:90 g Cl278:1 g PbCl 2¼ 1:27 g Cl(b) hydrogen in 4.50 g H 2 SO 42:016 g Hð4:50 g H 2 SO 4 Þ¼ 9:25 10 2 gH98:09 g H 2 SO 4(c) hydrogen in 5.45 10 22 molecules NH 3The conversion is: molecules NH 3 ! moles NH 3 ! gH5:45 10 22 1 mol3:024 g Hmolecules NH 36:022 10 23 ¼ 0:274 g Hmolecules mol NH 321. Percent composition(a) NaBr NaBr22.99 g79.90 g 22:99 g102:9g102.9 g 79:90 g102:9gð100Þ ¼ 22:34% Nað100Þ ¼ 77:65% Br(b) KHCO 3 K 39.10 g 39:10 gH 1.008 gð100Þ ¼ 39:06% K100:1g3O 48.00 g C 12.01 g 1:008 g100.1 gð100Þ ¼ 1:007% H100:1g 12:01 gð100Þ ¼ 12:00% C100:1g 48:00 gð100Þ ¼ 47:95% O100:1g-54-