Oleum or fuming sulfuric acid available commercially in concentrations ranging from 20 to 99.9% sulfur trioxide.
A. What is the percent by mass of sulfur trioxide (SO3) if oleum is expressed as 3H2SO4 . 5SO3? Show your solution.
B. Discuss at least three potentially hazardous features associated with concentrated sulfuric acid.
Consider the following information when formulating your answers.
To determine the percent by mass of SO3, you will need the molar mass of H2SO4 as well as SO3.
H2SO4 = 98.078 g/mol
SO3 = 80.063 g/mol
Now, we need to factor in the stoichiometric coefficients for each species in oleum to determine the molar mass of oleum.
Molar mass 3H2SO4 . 5SO3 = (98.078 x 3) + (80.063 x 5)
= 694.549 g/mol
The percent by mass of SO3 can then be calculated:
Percent SO3 = [(80.063 x 5) x 100]/694.549
A complete worked through solution for the percent by mass composition of this oleum related question is provided. Additionally, four hazardous features of concentrated sulfuric acid are detailed. Includes references.