Other Conversions:

·         Volume @ STP can be found using the conversion factor 22.4L/1mol

Ex.  If 6.0g of KCLO3 decompose according to the reaction below, what volume of O2 (@ STP) is produced?

1.      Balanced Eq’n: 2KClO3 à 2KCL + 3O2

2.      6.0g x 1mol/122.6g x 3/2 x 22.4L/1mol

= 1.6L

·         Heat can be included as a separate term in chemical reactions (enthalpy)…

·         Things to keep in mind when solving these eq’ns are that rxns that release heat are exothermic and rxns that absorb heat are endothermic. 

Ex.  Find the amount of heat released when 2.0mol of H2 are consumed accordingly to the reaction…

1.      Balanced Eq’n:  N2 +3H2 à 2NH3 + 46.2 kJ

2.      2.0mol x 46.2/3

=77kJ

Ex.  To find the amount of heat released when 675g of ammonia for according to the reaction below…

1.      Balanced Eq’n:  N2 + 3H2 à 2NH3 + 46.2kJ

2.      675g x 1mol/17g x 46.2/2

= 46.2kJ