Use the experimental molar mass to determine the molecular formula for compounds having the following analyses.
A.
41.39% carbon, 3.47% hydrogen, 55.14% Oxygen; experimental molar mass 116.07
I got C4H4O4 as the molecular formula.
Can someone check this for me?
Assume 116.07grams (I didn't check that)
carbon percent= 4*12/116= check
O percent= 4*16/116= it checks.
Notice how I checked it by working from the formula you proposed back to the original percents.
huh? so did i get my molecular forumla right? sorry im a bit confused on what you said.
To determine the molecular formula based on the given experimental molar mass and elemental analyses, you need to calculate the empirical formula first.
1. Convert the percentage of each element to grams:
- Carbon (C): 41.39% of 116.07 g/mol = 48.11 g
- Hydrogen (H): 3.47% of 116.07 g/mol = 4.03 g
- Oxygen (O): 55.14% of 116.07 g/mol = 63.93 g
2. Convert the grams of each element to moles using their respective molar masses:
- Carbon (C): 48.11 g / 12.01 g/mol = 4.00 mol
- Hydrogen (H): 4.03 g / 1.01 g/mol= 3.99 mol
- Oxygen (O): 63.93 g / 16.00 g/mol= 3.99 mol
3. Divide each mole value by the smallest mole value to obtain the simplest whole-number ratio:
- Carbon (C): 4.00 mol / 3.99 mol ≈ 1
- Hydrogen (H): 3.99 mol / 3.99 mol = 1
- Oxygen (O): 3.99 mol / 3.99 mol = 1
Since the empirical formula indicates there is one atom of each element, it matches the molecular formula. Therefore, C4H4O4 is indeed the molecular formula for the compound based on the given elemental analyses and experimental molar mass.
Thus, your answer of C4H4O4 as the molecular formula is correct.