<u>Answer:</u> The theoretical yield of acetanilide is 6.5 grams.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
.....(1)
Given mass of aniline =
(We know that:
)
Molar mass of aniline = 93.13 g/mol
Putting values in equation 1, we get:
![\text{Moles of aniline}=\frac{4.50g}{93.13g/mol}=0.048mol](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20aniline%7D%3D%5Cfrac%7B4.50g%7D%7B93.13g%2Fmol%7D%3D0.048mol)
- <u>For acetic anhydride:</u>
To calculate the mass of acetic anhydride, we use the equation:
![\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}](https://tex.z-dn.net/?f=%5Ctext%7BDensity%20of%20substance%7D%3D%5Cfrac%7B%5Ctext%7BMass%20of%20substance%7D%7D%7B%5Ctext%7BVolume%20of%20substance%7D%7D)
Volume of acetic anhydride = ![(1.25\times \text{Mass of aniline})=1.25\times 4.50=5.625mL](https://tex.z-dn.net/?f=%281.25%5Ctimes%20%5Ctext%7BMass%20of%20aniline%7D%29%3D1.25%5Ctimes%204.50%3D5.625mL)
Density of acetic anhydride = 1.08 g/mL
Putting values in above equation:
![1.08g/mL=\frac{\text{Mass of acetic anhydride}}{5.625mL}\\\\\text{Mass of acetic anhydride}=(1.08g/mL\times 5.625mL)=6.08g](https://tex.z-dn.net/?f=1.08g%2FmL%3D%5Cfrac%7B%5Ctext%7BMass%20of%20acetic%20anhydride%7D%7D%7B5.625mL%7D%5C%5C%5C%5C%5Ctext%7BMass%20of%20acetic%20anhydride%7D%3D%281.08g%2FmL%5Ctimes%205.625mL%29%3D6.08g)
Given mass of acetic anhydride = 6.08 g
Molar mass of acetic anhydride = 102.1 g/mol
Putting values in equation 1, we get:
![\text{Moles of acetic anhydride}=\frac{6.08g}{102.1g/mol}=0.06mol](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20acetic%20anhydride%7D%3D%5Cfrac%7B6.08g%7D%7B102.1g%2Fmol%7D%3D0.06mol)
The chemical equation for the reaction of aniline and acetic anhydride follows:
![C_6H_5NH_2+CH_3COOCOCH_3\rightarrow C_6H_5NHCOCH_3+CH_3COOH](https://tex.z-dn.net/?f=C_6H_5NH_2%2BCH_3COOCOCH_3%5Crightarrow%20C_6H_5NHCOCH_3%2BCH_3COOH)
By Stoichiometry of the reaction:
1 mole of aniline reacts with 1 mole of acetic anhydride
So, 0.048 moles of aniline will react with =
of acetic anhydride
As, given amount of acetic anhydride is more than the required amount. So, it is considered as an excess reagent.
Thus, aniline is considered as a limiting reagent because it limits the formation of product.
By Stoichiometry of the reaction:
1 mole of aniline produces 1 mole of acetanilide
So, 0.048 moles of aniline will produce =
of acetanilide
Now, calculating the theoretical yield of acetanilide by using equation 1:
Moles of acetanilide = 0.048 moles
Molar mass of acetanilide = 135.17 g/mol
Putting values in equation 1, we get:
![0.048mol=\frac{\text{Mass of acetanilide}}{135.17g/mol}\\\\\text{Mass of acetanilide}=(0.048mol\times 135.17g/mol)=6.5g](https://tex.z-dn.net/?f=0.048mol%3D%5Cfrac%7B%5Ctext%7BMass%20of%20acetanilide%7D%7D%7B135.17g%2Fmol%7D%5C%5C%5C%5C%5Ctext%7BMass%20of%20acetanilide%7D%3D%280.048mol%5Ctimes%20135.17g%2Fmol%29%3D6.5g)
Hence, the theoretical yield of acetanilide is 6.5 grams.