Question

If 1.332 mol of C4H10 are reacted with 6.504 mol of O2, how many mol of the excess reagent will remain unreacted? 2 C4H10 + 13 O2 ——> 8 CO2 + 10 H2O MM: 58.1 32.0 44.0 18.0

Answer 1

Answer: The number of moles of excess reagent remain unreacted will be, 6.004 moles.

Explanation : Given,

Moles of $C_4H_{10}$ = 1.332 mol

Mass of $O_2$ = 6.504 mol

First we have to calculate the limiting and excess reagent.

The balanced chemical equation is:  

$C_4H_{10}+13O_2\rightarrow 10H_2O+8CO_2$

From the balanced reaction we conclude that

As, 13 mole of $O_2$ react with 1 mole of $C_4H_{10}$

So, 6.504  moles of $O_2$ react with $\frac{6.504}{13}=0.5003$ moles of $C_4H_{10}$

From this we conclude that, $C_4H_{10}$ is an excess reagent because the given moles are greater than the required moles and $O_2$ is a limiting reagent and it limits the formation of product.

Number of moles remain unreacted = 6.504 mol - 0.5003 mol = 6.004 mol

Therefore, the number of moles of excess reagent remain unreacted will be, 6.004 moles.