Find the total number of atoms in a sample of cocaine hydrochloride, C17H22ClNO4, of mass 24.0 mg

Answer 1

24.0 mg x 1 g/1000 mg x 1 mol/339.8 g x 6.02x10²³ molecules/mole x 45 atoms/molecule = # atoms

Answer should be around 2x10²¹ atoms

Answer 2

In order to go from mass to number of atoms, you are first going to have to go through moles. First, then, we calculate the molar mass of cocaine hydrochloride and use that to calculate how many moles are in the sample.

Molar mass of C17H22ClNO4 = 17*12.01 + 22*1.01 + 35.45 + 14.01 + 4*16.00 = 339.85 g/mol

Now to find the number of moles in the sample:

24.0 mg * (1 g/ 1000 mg) * (1 mol / 339.85 g) = 7.06e-5 mol

Now you can use Avogadro's number to find the number of molecules in the sample, then the number of atoms by multiplying by the number of atoms in each molecule.

7.06e-5 mol * (6.022e23 molecules / 1 mol) * (45 atoms / 1 molecule) = 1.91e21 atoms

Answer 3

Hello Elle,

The first step to answering this question is to find out how many moles are in 24mg of cocaine hydrochloride.

To do this we need to fid the molecular weight of our compound:

1. Carbon 12amu, Hydrogen 1amu, Chlorine 35.4amu, Nitrogen 14amu, Oxygen 16amu
2. The total molecular weight should be 339.4amu

Now the formula for calculating the amount of moles is: [# of moles] = [grams]/[gram formula mass] (this is the molecular weight of the compound)

1. [# of moles] = [24x10^-3 g] (Units need to be grams, not milligrams)/[339.4amu] = [7.07x10^-5 moles]

Now that you know the number of moles, you can multiply by Avogadro's number to find the number of atoms in the compound. There are 6.022x10²³ atoms in one mole of any substance.

1. 7.07x10^-5 moles of cocaine hydrochloride x 6.022x10²³ atoms per 1 mole = 4.2 x 10¹⁹ atoms

Let me know if you have any questions!

Aric