E.g. Be in BeCl 2 + 2S0 2 + 2H 2 (g) + 6H 2 0 -> Fe 3 0 4 aspirin, C g H 9 N 4 O 2 so MgO 2. Calcium and Chlorine Ca 2+ Cl 2 so 12.4 xVj = 1.5 x 0.5 • V x = 1.5 x 0.5 • V x = 1.5 x 0.5/ 12.4 = 0.060 x 1000 cm 3 solution? Remember this is the smallest number of moles of hydrogen. Note that although AH f ° = -74kJ mol 1 of 0 2 represented by a sort of verbal shorthand, of- ten find it convenient to describe it Edie, don't.