when 21.6g of benzene and an excess of HNO3 are used, what is the theoretical yield of nitrobenzene? Is 30g of nitrobenzene is recovered, what is the percent recovery?
To find the theoretical yield of nitrobenzene, we need to calculate the molecular formula of benzene and nitrobenzene.
Benzene has a molecular formula of C6H6, and nitrobenzene has a molecular formula of C6H5NO2.
Step 1: Find the molar mass of benzene.
Molar mass of carbon (C) = 12.01 g/mol
Molar mass of hydrogen (H) = 1.01 g/mol
Molar mass of benzene = 6(C) + 6(H)
= (6 x 12.01) + (6 x 1.01)
= 72.06 + 6.06
= 78.12 g/mol
Step 2: Convert the mass of benzene to moles.
Moles of benzene = Mass of benzene / Molar mass of benzene
= 21.6 g / 78.12 g/mol
= 0.2768 mol
Step 3: Determine the stoichiometry between benzene and nitrobenzene.
From the balanced equation:
C6H6 + HNO3 → C6H5NO2 + H2O
The stoichiometry shows that for every 1 mole of benzene, we get 1 mole of nitrobenzene.
Step 4: Calculate the theoretical yield of nitrobenzene.
Theoretical yield of nitrobenzene = Moles of benzene x Molecular mass of nitrobenzene
= 0.2768 mol x (6 x 12.01 + 5 x 1.01 + 2 x 16.00)
= 0.2768 mol x 123.13 g/mol
= 34.05 g
Therefore, the theoretical yield of nitrobenzene is 34.05 g.
To find the percent recovery:
Percent recovery = (Actual yield / Theoretical yield) x 100
Given that the actual yield is 30 g, we can calculate the percent recovery:
Percent recovery = (30 g / 34.05 g) x 100
≈ 88.1%
Therefore, the percent recovery of nitrobenzene is approximately 88.1%.
To calculate the theoretical yield of nitrobenzene, we need to first determine the balanced chemical equation for the reaction between benzene (C6H6) and nitric acid (HNO3) to produce nitrobenzene (C6H5NO2).
C6H6 + HNO3 -> C6H5NO2 + H2O
From the balanced equation, we can see that the stoichiometric ratio between benzene and nitrobenzene is 1:1. This means that for every 1 mole of benzene, we should obtain 1 mole of nitrobenzene.
To find the moles of benzene used, we need to divide the given mass of benzene by its molar mass:
molar mass of benzene (C6H6) = 78.11 g/mol
moles of benzene = mass of benzene / molar mass of benzene
moles of benzene = 21.6 g / 78.11 g/mol
If we assume that the reaction goes to completion, meaning all the benzene is converted to nitrobenzene, the moles of nitrobenzene produced will be the same as the moles of benzene used.
Thus, the theoretical yield of nitrobenzene is 21.6 g.
To calculate the percent recovery, we use the following formula:
Percent recovery = (Actual yield / Theoretical yield) × 100
Given that the actual yield of nitrobenzene is 30g, we can substitute the values into the formula:
Percent recovery = (30 g / 21.6 g) × 100
Percent recovery ≈ 138.89%
Therefore, the percent recovery of nitrobenzene is approximately 138.89%.