If 84 g of CO2 were produced, how many grams of butanol were burned?

C4H9OH + 6O2 ==> 4CO2 + 5H2O

mols CO2 = grams CO2/molar mass CO2.
Use the coefficients to convert mols CO2 to mols butanol.
Now convert mols butanol to grams butanol.
g = mols butanol x molar mass butanol.

To determine the grams of butanol burned, we need to use the balanced equation for the combustion of butanol. Since you provided the grams of CO2 produced, we will need to calculate the grams of butanol burned.

The balanced equation for the combustion of butanol is:
2 C4H9OH + 13 O2 → 8 CO2 + 10 H2O

From the balanced equation, we can see that for every 8 moles of CO2 produced, we need 2 moles of C4H9OH (butanol). So, the molar ratio of CO2 to C4H9OH is 8:2.

To calculate the grams of butanol burned, we can use the molar mass of CO2 and the molar ratio from the balanced equation.

The molar mass of CO2 is:
C: 12.01 g/mol
O: 16.00 g/mol (2 atoms)

So, the molar mass of CO2 is:
12.01 g/mol (C) + 2 * 16.00 g/mol (O) = 44.01 g/mol

Now, we can set up a proportion using the molar ratio and the molar mass of CO2:

(84 g CO2) / (44.01 g/mol CO2) = x g butanol / (58.12 g/mol butanol)

Simplifying the proportion:

(84 g CO2) * (58.12 g/mol butanol) = (44.01 g/mol CO2) * x g butanol

4886.08 g⋅mol butanol = 44.01 g CO2⋅x g butanol

x g butanol = (4886.08 g⋅mol butanol) / (44.01 g CO2)
x g butanol ≈ 111.08 g

Therefore, it is estimated that approximately 111.08 grams of butanol were burned.

To determine the number of grams of butanol burned, we need some additional information. Specifically, we need to know the balanced chemical equation for the combustion of butanol.

However, I can provide a general explanation of how to approach this type of problem.

1. Write the balanced chemical equation: Determine the balanced chemical equation for the combustion of butanol. This equation shows the reactants and products involved in the reaction.

2. Determine the molar ratio: Once you have the balanced equation, identify the stoichiometric coefficients for CO2 and butanol. This ratio will tell you how many moles of butanol are required to produce a certain number of moles of CO2.

3. Calculate the number of moles: Convert the given mass of CO2 to moles using the molar mass of CO2.

4. Use the molar ratio: From the balanced equation, use the molar ratio to determine the number of moles of butanol required to produce the given number of moles of CO2.

5. Convert to grams: Finally, convert the number of moles of butanol to grams by multiplying by the molar mass of butanol.

By following these steps, you can determine the mass of butanol burned when given the mass of CO2 produced.