<u>Answer:</u> The percent yield of the reaction is 91.8 %
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
.....(1)
- <u>For
:</u>
Given mass of
= 4.0 g
Molar mass of
= 63.12 g/mol
Putting values in equation 1, we get:
![\text{Moles of }B_5H_9=\frac{4g}{63.12g/mol}=0.0634mol](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20%7DB_5H_9%3D%5Cfrac%7B4g%7D%7B63.12g%2Fmol%7D%3D0.0634mol)
Given mass of oxygen gas = 10.0 g
Molar mass of oxygen gas = 32 g/mol
Putting values in equation 1, we get:
![\text{Moles of oxygen gas}=\frac{10g}{32g/mol}=0.3125mol](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20oxygen%20gas%7D%3D%5Cfrac%7B10g%7D%7B32g%2Fmol%7D%3D0.3125mol)
The chemical equation for the reaction of
and oxygen gas follows:
![2B_5H_9+12O_2\rightarrow 5B_2O_3+9H_2O](https://tex.z-dn.net/?f=2B_5H_9%2B12O_2%5Crightarrow%205B_2O_3%2B9H_2O)
By Stoichiometry of the reaction:
12 moles of oxygen gas reacts with 2 moles of ![B_2H_5](https://tex.z-dn.net/?f=B_2H_5)
So, 0.3125 moles of oxygen gas will react with =
of ![B_2H_5](https://tex.z-dn.net/?f=B_2H_5)
As, given amount of
is more than the required amount. So, it is considered as an excess reagent.
Thus, oxygen gas is considered as a limiting reagent because it limits the formation of product.
By Stoichiometry of the reaction:
12 moles of oxygen gas produces 5 moles of ![B_2O_3](https://tex.z-dn.net/?f=B_2O_3)
So, 0.3125 moles of oxygen gas will produce =
of water
Now, calculating the mass of
from equation 1, we get:
Molar mass of
= 69.93 g/mol
Moles of
= 0.130 moles
Putting values in equation 1, we get:
![0.130mol=\frac{\text{Mass of }B_2O_3}{69.63g/mol}\\\\\text{Mass of }B_2O_3=(0.130mol\times 69.63g/mol)=9.052g](https://tex.z-dn.net/?f=0.130mol%3D%5Cfrac%7B%5Ctext%7BMass%20of%20%7DB_2O_3%7D%7B69.63g%2Fmol%7D%5C%5C%5C%5C%5Ctext%7BMass%20of%20%7DB_2O_3%3D%280.130mol%5Ctimes%2069.63g%2Fmol%29%3D9.052g)
To calculate the percentage yield of
, we use the equation:
![\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100](https://tex.z-dn.net/?f=%5C%25%5Ctext%7B%20yield%7D%3D%5Cfrac%7B%5Ctext%7BExperimental%20yield%7D%7D%7B%5Ctext%7BTheoretical%20yield%7D%7D%5Ctimes%20100)
Experimental yield of
= 8.32 g
Theoretical yield of
= 9.052 g
Putting values in above equation, we get:
![\%\text{ yield of }B_2O_3=\frac{8.32g}{9.052g}\times 100\\\\\% \text{yield of }B_2O_3=91.8\%](https://tex.z-dn.net/?f=%5C%25%5Ctext%7B%20yield%20of%20%7DB_2O_3%3D%5Cfrac%7B8.32g%7D%7B9.052g%7D%5Ctimes%20100%5C%5C%5C%5C%5C%25%20%5Ctext%7Byield%20of%20%7DB_2O_3%3D91.8%5C%25)
Hence, the percent yield of the reaction is 91.8 %