(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Sulfur dioxide reacts with the oxygen in humid air to produce sulfur trioxide.

After the reaction, how many moles are left of: SO_{2}, O_{2}and how many moles of SO_{3}were created?

2. Relevant equations

2 SO_{2}+ O_{2}--> 2 SO_{3}

3. The attempt at a solution

The limiting reactant is SO_{2}, so we know that it will fully react and we'll end up with 0 moles of SO_{2}.

From previous steps, I know that I have 0.1021 moles of SO_{2}, and 0.0857 moles of O_{2}. I also know that after the reaction, I will have 0.03474 moles of O_{2}left.

I can't, for the life of me, figure out how many moles of SO_{3}I'll have at the end.

Shouldn't there be some conservation of mass? I keep finding that I'll have 0.1021 moles of SO_{3}at the end, which is the same amount as the SO_{2}.

Is this correct? I seem to think that the reaction with O_{2}will have changed the number of moles.

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# Homework Help: Moles remaining after a reaction

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