Calculate the number of moles of Carbon in 27.6g C4H9OH.

# mols C4H9OH = grams/molar mass.

Then # moles C is 4x that.

To calculate the number of moles of carbon in a given compound, we need to know the molar mass of the compound and the mass of carbon in it.

First, let's calculate the molar mass of C4H9OH (butanol):
C: 4 atoms x atomic mass of C = 4 x 12.01 g/mol = 48.04 g/mol
H: 9 atoms x atomic mass of H = 9 x 1.01 g/mol = 9.09 g/mol
O: 1 atom x atomic mass of O = 1 x 16.00 g/mol = 16.00 g/mol

The molar mass of C4H9OH is the sum of these masses:
48.04 g/mol + 9.09 g/mol + 16.00 g/mol = 73.13 g/mol

Now, we can calculate the number of moles of C in 27.6 g of C4H9OH using the following steps:

Step 1: Calculate the mass of carbon in C4H9OH.
To do this, we need to find the percent composition of carbon in C4H9OH.

Mass of carbon = (mass of carbon / total mass of C4H9OH) x 100

Mass of carbon = (48.04 g/mol / 73.13 g/mol) x 100 = 65.7%

Step 2: Calculate the number of moles of carbon.
Number of moles = mass of carbon / molar mass of carbon

Number of moles = (27.6 g) x (65.7% / 100) / 12.01 g/mol

Number of moles = 3.72 moles

Therefore, there are approximately 3.72 moles of carbon in 27.6 g of C4H9OH.