Part of the SO2 that is introduced into the atmosphere by combustion of sulfur containing compounds ends up being converted to sulfuric acid, H2SO4. How many moles of H2SO4can be formed from 5.0 mol SO2., 4.0 mol O2 and 20.0 mol H2O?

5 mol.

Explanation:

Equation of the reaction

2SO2 + 2H2O + O2 --> 2H2SO4

By stoichiometry, 2 moles of SO2 reacted with 2 moles of water and 1 mole of O2 to give 2 mole of sulphuric acid.

Number of moles:

5.0 mol SO2

4.0 mol O2

20.0 mol H2O

Calculating the limiting reagent,

5 mol of SO2 * 1 mol of O2/2 mol of SO2

= 2.5 mol of O2(4 mol of O2 is present)

5 mol of SO2 * 2 mol of H2O/2 mol of SO2

= 5 mol of H2O(20 mol of H2O)

SO2 is the limiting reagent.

Therefore, number of moles of H2SO4 = 5 mol of SO2 * 2 mol of H2SO4/2 mol of SO2

= 5 mol of H2SO4.