Question

given the reaction 2SO2+O2=2SO3 if 4 moles of SO2 are used then how many moles of SO3 are made?
4moles
2moles
1mole
1/2 mole

Answer 1

if you look at the coefficients, they're both the same, 2, therefore the moles used and produced will be equivalent.

If you wanna use math to show this you can build a relationship between them using proportions/ratios.


For a general reaction, aA + bB <-> cC

where a,b and c are the stoichiometric coefficients and A,B and C are the species,

\[\frac{ Moles of A }{ a }=\frac{ Moles of B }{ b }=\frac{ Moles of C }{ c }\]

and so you can plug in your knowns, and solve (algebraically) for your unknown.

Answer 2

4 moles.