To balance the chemical equation for the reaction of sulfur dioxide SO2 with oxygen O2 to form sulfur trioxide SO3 , follow these steps:1. Write the unbalanced equation: SO2 + O2 SO32. Count the number of atoms of each element on both sides of the equation: Left side: 1 S, 2 O in SO2 + 2 O in O2 = 1 S, 4 O Right side: 1 S, 3 O in SO3 3. Balance the sulfur atoms first. They are already balanced, with one sulfur atom on each side of the equation.4. Balance the oxygen atoms. There are 4 oxygen atoms on the left side and 3 on the right side. To balance the oxygen atoms, multiply the SO3 by 2: SO2 + O2 2SO35. Now, count the atoms again: Left side: 1 S, 2 O in SO2 + 2 O in O2 = 1 S, 4 O Right side: 2 S, 6 O in 2SO3 6. The oxygen atoms are balanced, but now there are 2 sulfur atoms on the right side. To balance the sulfur atoms, multiply the SO2 by 2: 2SO2 + O2 2SO37. Count the atoms one last time: Left side: 2 S, 4 O in 2SO2 + 2 O in O2 = 2 S, 6 O Right side: 2 S, 6 O in 2SO3 Now, the chemical equation is balanced:2SO2 + O2 2SO3