Answers to Chapter 2

30 mass reactants = mass products = 124.8 g

32 % H in both cases is 11.2%. 
Or
Mass oxygen/Mass hydrogen = 7.9 in both cases

34 a 1.74 g compound
     b  0.76 g ureacted sulfur

42  a  88 protons, 86 electrons, 140 neutrons
      b  ratio = 14.2564

50  51.99 u (note that this is close to the value of the most common isotope)

56 a 6 molecules
1H35Cl mass 36; 1H37Cl mass 38; 2H35Cl mass 37; 2H37Cl mass 39
3H35Cl mass 38; 3H37Cl mass 40
     b  The first is most common and the second is second most common

58  a  7.91x10^19 argon atoms
      b  91.2 g/mol
      c  14.67 g Al
60  2.55x10^24 atoms

62 4.37x10^12 atoms lead per lungful of air

76	186.98 g alloy