Maleic acid has the empirical formula CHO. If the molar mass of oxalic acid is 116.1 g/mol, what is the molecular formula of maleic acid? [C=12.0g/mol, H = 1.01 g/mol, O = 16.0 g/mol] a) CHO b)C_2H_2O_2 c) C_6H_12O_2 d) C_4H_4O_4 e) C_3H_6O_3
The Correct Answer and Explanation is :
The given empirical formula of maleic acid is CHO, and we need to find its molecular formula. Additionally, we are told that the molar mass of oxalic acid is 116.1 g/mol, and we are given atomic masses for carbon (C), hydrogen (H), and oxygen (O).
Step 1: Calculate the molar mass of the empirical formula
The molar mass of the empirical formula CHO is calculated by adding the atomic masses of each element:
- Carbon (C) = 12.0 g/mol
- Hydrogen (H) = 1.01 g/mol
- Oxygen (O) = 16.0 g/mol
So, the molar mass of the empirical formula CHO is:
[
12.0 \, \text{g/mol} + 1.01 \, \text{g/mol} + 16.0 \, \text{g/mol} = 29.01 \, \text{g/mol}
]
Step 2: Determine the ratio of the molecular mass to the empirical formula mass
We are told that the molar mass of maleic acid is 116.1 g/mol. To find the ratio between the molar mass of the molecular formula and the empirical formula mass:
[
\text{Ratio} = \frac{\text{Molar mass of maleic acid}}{\text{Empirical formula mass}} = \frac{116.1 \, \text{g/mol}}{29.01 \, \text{g/mol}} \approx 4
]
Step 3: Determine the molecular formula
Since the ratio is approximately 4, this means the molecular formula of maleic acid is 4 times the empirical formula. Therefore, we multiply the empirical formula (CHO) by 4:
[
\text{Molecular formula} = (CHO) \times 4 = C_4H_4O_4
]
Step 4: Conclusion
The molecular formula of maleic acid is C₄H₄O₄, which corresponds to option d.
Thus, the correct answer is d) C₄H₄O₄.