Answer:
The molar mass of vitamin C is 176.12 g/mol.
The number of moles in 500.0 mg vitamin C is 2.84x10^-3 mol
The number of moles in 500.0 mg vitamin C is 1.71x10^21 molecules
Explanation:
Determine the molar mass
The chemical formula for vitamin C is C6H8O6
The molar mass of C6H8O6: The atomic mass of C is 12.01 g/mol , H is 1.008 g/mol and O is 16.00 g/mol. We multiply each atomic mass by the number present in the chemical formula and then add them together to get the molar mass. The molar mass of C6H8O6 then is:
C6H8O6 6 C × 12.01 g/mol C = 72.06 g/mol
8 H × 1.008 g/mol H = 8.064 g/mol
6 O × 16.00 g/mol O = 96.00 g/mol
Sum = 176.124 g/mol
Calculate the number of moles
Given:
mass = 500.0 mg
molar mass = 176.12 g/mol
Solve for number of moles
500 mg * 10^-3 g / 1 mg * 1 mol / 176.12 g = 2.84x10^-3 mol
Calculate the number of molecules
Given:
moles = 2.84x10-3 mol
Avogadro's number = 6.022x1023 molecules
Solve for number of molecules
2.84x10^-3 mol (6.022x10^23 molecules/ 1 mol) = 1.71x10^21 molecules