Rubbing alcohol often contains propanol, C3H7OH. Suppose you have an 85.9 g sample.

a) How many carbon atoms are in the sample?

b) How many hydrogen atoms are in the sample?

c) How many oxygen atoms are in the sample?

For a, I have tried dividing 85.9 by the total mass, 60.09502, which gave me 1.429409069.After this, I multiplied by Avagadro's constant, 6.02 x 10^23, which gave me the total atoms in propanol. However, I am not sure how to find the atoms in each individual element.

How many molecules do you have?

Well how much mass in a mol?

3*12 + 7*1 + 16 + 1 = 60 grams for 6.022*10^23 molecules
so
we have
6.022*10^23 * 85.9/60
= 8.62*10^23 molecules
each of those molecules has 3 carbon atoms
3*8.62*10^23 = 25.9 *10^23
=2.59 * 10^24 carbon atoms

Why would you multiply that number by 3?

Look at the formula of C3H7OH. For every molecule of C3H7OH, you have 3 C atoms. Multiply by 8 to find the number of H atoms and multiply by 1 for find O atoms.

To find the number of atoms in each individual element in the propanol sample, you need to calculate the moles of each atom present and then use Avogadro's constant to convert moles to atoms.

First, let's calculate the moles of propanol in the sample by dividing the mass of the sample by its molar mass.

a) Number of carbon atoms:
The molar mass of carbon (C) is approximately 12.01 g/mol. Divide the mass of the sample by the molar mass of carbon to get the moles of carbon atoms.

Moles of carbon atoms = Mass of sample (g) / Molar mass of carbon (g/mol)

Moles of carbon atoms = 85.9 g / 12.01 g/mol

Next, multiply the moles of carbon atoms by Avogadro's constant to convert moles to atoms:

Number of carbon atoms = Moles of carbon atoms × Avogadro's constant

b) Number of hydrogen atoms:
The molar mass of hydrogen (H) is approximately 1.008 g/mol. Divide the mass of the sample by the molar mass of hydrogen to get the moles of hydrogen atoms.

Moles of hydrogen atoms = Mass of sample (g) / Molar mass of hydrogen (g/mol)

Moles of hydrogen atoms = 85.9 g / 1.008 g/mol

Next, multiply the moles of hydrogen atoms by Avogadro's constant to convert moles to atoms:

Number of hydrogen atoms = Moles of hydrogen atoms × Avogadro's constant

c) Number of oxygen atoms:
The molar mass of oxygen (O) is approximately 16.00 g/mol. Divide the mass of the sample by the molar mass of oxygen to get the moles of oxygen atoms.

Moles of oxygen atoms = Mass of sample (g) / Molar mass of oxygen (g/mol)

Moles of oxygen atoms = 85.9 g / 16.00 g/mol

Next, multiply the moles of oxygen atoms by Avogadro's constant to convert moles to atoms:

Number of oxygen atoms = Moles of oxygen atoms × Avogadro's constant

Performing these calculations will give you the number of carbon, hydrogen, and oxygen atoms in the given sample.