What is the limiting reactant when 4.5 moles of aluminum react with 6.7 moles of oxygen gas? (4 points)

Unbalanced equation: Al + O2 → Al2O3
@TheSmartOne

Question

What is the limiting reactant when 4.5 moles of aluminum react with 6.7 moles of oxygen gas? (4 points)

Unbalanced equation: Al + O2 → Al2O3 
@TheSmartOne

thesmartone · Answer

Can you first find the balanced equation?

anonymous · Answer

https://vcsohio.brainhoney.com/MathML/Image.ashx?data=4Al%20%2B%203O_2%20-%3E2Al_2O_3

thesmartone · Answer

Correct :)

thesmartone · Answer

Well, so do you see how there are less moles of $\sf O_2$ that react with $\sf Al$?  That means that there will be an excess of $\sf O_2$ because there are more moles available/

anonymous · Answer

So Al is the limiting reactant?

anonymous · Answer

@TheSmartOne

thesmartone · Answer

Yes :)

thesmartone · Answer

Do you want to know the math way too?

anonymous · Answer

For educational purposes, yes.

thesmartone · Answer

$$\sf \frac{ 4.5 ~mol ~Al}{ 1 } \times \frac{ 3~mol~O_2 }{ 4~mol Al }= 3.2~ mol~O_2$$

And since we have been given 6.7 mols but we are only using 3.2 moles, we can obviously say that $\sf O_2$ is in excess.

thesmartone · Answer

And that $\sf Al$ is the limiting reactant $\LARGE\ddot\smile$

anonymous · Answer

Thanks a lot!!

anonymous · Answer

@TheSmartOne  Where did you get the 4 molAl?

anonymous · Answer

I need to know this for another question. @TheSmartOne

thesmartone · Answer

Sorry was afk.

thesmartone · Answer

@brostep0s

I took it from the balanced equation