A sample of toluene, C7H8 has a mass of 74.5 g.
How many carbon atoms does it contain?
How many hydrogen atoms does it contain?
My work:
I get 3.41 x 10^24 for carbon atoms
And 3.90 x 10^24 for hydrogen atoms.
Is this correct?
Both are correct! Good work!
To determine the number of carbon and hydrogen atoms in a sample of toluene, you can use the given information and the molar mass of each element.
The molar mass of carbon (C) is 12.01 g/mol, and the molar mass of hydrogen (H) is 1.008 g/mol. To calculate the number of moles of each element in the sample of toluene, you need to divide the mass of each element by its molar mass.
For carbon atoms:
Number of moles of carbon = mass of carbon / molar mass of carbon
Number of moles of carbon = 74.5 g / 12.01 g/mol
Number of moles of carbon ≈ 6.21 moles
To find the number of atoms, you can use Avogadro's number, which states that there are approximately 6.022 x 10^23 atoms in one mole of a substance. Therefore, you can find the number of carbon atoms by multiplying the number of moles of carbon by Avogadro's number.
Number of carbon atoms = number of moles of carbon × Avogadro's number
Number of carbon atoms ≈ 6.21 moles × 6.022 x 10^23 atoms/mole
Number of carbon atoms ≈ 3.74 x 10^24 atoms
For hydrogen atoms, you can follow a similar process:
Number of moles of hydrogen = mass of hydrogen / molar mass of hydrogen
Number of moles of hydrogen = 74.5 g / 1.008 g/mol
Number of moles of hydrogen ≈ 73.81 moles
Number of hydrogen atoms = number of moles of hydrogen × Avogadro's number
Number of hydrogen atoms ≈ 73.81 moles × 6.022 x 10^23 atoms/mole
Number of hydrogen atoms ≈ 4.44 x 10^25 atoms
Therefore, the correct number of carbon atoms is approximately 3.74 x 10^24 atoms and the correct number of hydrogen atoms is approximately 4.44 x 10^25 atoms. Your calculations seem to be incorrect.