I don't understand where to start first. Can you break it down for me?

Ascorbic acid, also known as vitamin C, has a percentage composition of 40.9% C, 4.58% H, and 54.5% O. The molar mass of ascorbic acid is 176.1 g/mol. Determine the empirical and molecular formulas

assume 100 grams, then find the moles of C, H, O from that.

Then divide each of those moles by the smallest moles of C, H, O.

You should end up with the ratio of the elements. Now, take the empirical formula mass, divide it into the mole mass given, it will tell you what to multiply the ratio by.

Ok Thankyou so much for breaking it down. I think I got it. (:

Sure! Let's break it down step by step to determine the empirical and molecular formulas of ascorbic acid.

1. Start by assuming you have a 100g sample of ascorbic acid.
- This means that 40.9 grams of the sample are carbon (C), 4.58 grams are hydrogen (H), and 54.5 grams are oxygen (O).

2. Calculate the moles of each element:
- To do this, divide the mass of each element by its molar mass.
- Moles of carbon (C) = 40.9g / 12.01 g/mol = 3.40 mol
- Moles of hydrogen (H) = 4.58g / 1.008 g/mol = 4.54 mol
- Moles of oxygen (O) = 54.5g / 16.00 g/mol = 3.41 mol

3. Determine the ratio of moles:
- Divide the number of moles of each element by the smallest number of moles.
- Ratio of moles of carbon (C): 3.40 mol / 3.40 mol = 1
- Ratio of moles of hydrogen (H): 4.54 mol / 3.40 mol = 1.34
- Ratio of moles of oxygen (O): 3.41 mol / 3.40 mol = 1.00

4. Determine the empirical formula:
- The empirical formula represents the lowest whole number ratio of elements in a compound.
- Based on the ratios of moles, the empirical formula for ascorbic acid is CH1.34O1, which is not a whole number ratio.

5. Convert the subscripts to whole numbers:
- Multiply all the subscripts by 2 to get whole numbers.
- The empirical formula for ascorbic acid becomes C2H3O2.

6. Determine the molecular formula:
- To find the molecular formula, you need to know the molar mass of the compound.
- The given molar mass of ascorbic acid is 176.1 g/mol.
- Divide the molar mass of the compound by the empirical formula mass (C2H3O2) to get the multiplier.
- Molecular formula multiplier = 176.1 g/mol / (12.01 g/mol * 2 + 1.008 g/mol * 3 + 16.00 g/mol * 2) = 2.00

7. Multiply the subscripts in the empirical formula by the molecular formula multiplier:
- C2H3O2 * 2 = C4H6O4

So, the empirical formula of ascorbic acid is C2H3O2, and the molecular formula is C4H6O4.