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The elemental mass percent composition of ascorbic acid (vitamin C ) is 40.92% C , 4.58% H , and 54.50% O . Determine the empirical formula of ascorbic acid.

User Dolfa
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Final answer:

The empirical formula of ascorbic acid is C3H4O3. The chemical formula of ascorbic acid is C6H8O6.

Step-by-step explanation:

To determine the empirical formula of ascorbic acid (vitamin C), we need to find the ratio of the elements present in the compound. Given that the mass percent composition of ascorbic acid is 40.92% C, 4.58% H, and 54.50% O, we can assume we have 100 grams of ascorbic acid. This means we have 40.92 grams of carbon, 4.58 grams of hydrogen, and 54.50 grams of oxygen.

We can convert the grams to moles by dividing by the molar mass of each element: C (12.01 g/mol), H (1.01 g/mol), and O (16.00 g/mol). This gives us approximately 3.41 moles of C, 4.53 moles of H, and 3.41 moles of O.

The empirical formula is the simplest whole number ratio of the elements, so we divide the moles of each element by the smallest number of moles (3.41 moles of C). This gives us approximately 1 mole of C, 1.33 moles of H, and 1 mole of O. We multiply these values by a factor of 3 to get whole number ratios, giving us the empirical formula of C3H4O3.

To determine the chemical formula, we need to compare the empirical formula mass (molar mass of empirical formula) to the experimentally determined molecular mass (176 amu). The empirical formula mass can be calculated by adding the atomic masses of the elements in the empirical formula: 3C (3*12.01) + 4H (4*1.01) + 3O (3*16.00) = 88.06 g/mol.

Therefore, the molecular formula of ascorbic acid is C6H8O6.

User Nir Friedman
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