According to the below equation, how many moles of SO2 are required to generate 1.43*1024 water molecules?

2H2S+SO2→3S+2H2O

Make sure the equation is always balanced first. (It is balanced for this question already) 6.022 x 10^23 is Avogadro's number. In one mole of anything there is always 6.022 x 10^23 molecules, formula units, atoms. For one mol of an element / compound use molar mass (grams).

Multiply everything on the top = 8.61x10^47

Multiple everything on bottom = 1.20x10^24

Divide top and bottom = 7.15x10^23

Answer: 7.15x10^23 mol SO2