Calculate the percentage by mass of the indicated element in the following compounds: b. hydrogen in ascorbic acid, HC6H7O6, also known as vitamin C

Verified step by step guidance

1. Determine the molar mass of ascorbic acid (HC6H7O6). This involves adding the atomic masses of all the atoms in the formula: 1 hydrogen (H), 6 carbons (C), 7 additional hydrogens (H), and 6 oxygens (O).
2. Calculate the total mass of hydrogen in the compound. Since there are 8 hydrogen atoms in total in the formula of ascorbic acid, multiply the atomic mass of hydrogen by 8.
3. Use the molar mass of ascorbic acid calculated in step 1 to find the percentage by mass of hydrogen. This is done by dividing the total mass of hydrogen (from step 2) by the molar mass of ascorbic acid and then multiplying by 100 to convert it to a percentage.
4. Ensure the units are consistent when performing the calculations. All masses should be in grams (g) to accurately compute the percentage.
5. Interpret the result as the percentage by mass of hydrogen in ascorbic acid, which indicates how much of the compound's mass is due to hydrogen atoms.

Key Concepts

Molar Mass Calculation

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). To calculate the molar mass of a compound, sum the atomic masses of all the atoms in its molecular formula. For ascorbic acid (HC6H7O6), this involves adding the molar masses of hydrogen, carbon, and oxygen based on their respective quantities in the formula.

Percentage by Mass

Percentage by mass is a way to express the concentration of an element in a compound. It is calculated by dividing the mass of the element by the total molar mass of the compound and then multiplying by 100. This calculation provides insight into the composition of the compound and is essential for understanding its chemical properties.

Empirical and Molecular Formulas

The empirical formula represents the simplest whole-number ratio of elements in a compound, while the molecular formula shows the actual number of atoms of each element in a molecule. In the case of ascorbic acid, understanding its molecular formula (HC6H7O6) is crucial for determining the mass contributions of hydrogen and other elements, which is necessary for calculating the percentage by mass of hydrogen.