PROBLEMS 1. Correct the following gas volumes from the initial conditions to the
new conditions (assume the temperature remains constant):
a. 100 ml oxygen at 80 cm Hg to 76 cm Hg
b. 50 ml hydrogen at 740 mm Hg to 760 mm Hg
c. 500 ml sulfur dioxide at 780 mm Hg to SP
d. 150 ml nitrogen at BP to 80 cm Hg
Correct following gas volumes from the initial conditions to the

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.