Question

The empirical formula of a compound is CH$_2$O. If 0.0835 moles of the compound contain 1 g of hydrogen, the molecular formula of the compound is

• A. C$_2$H$_4$O$_2$
• B. CgHgOg
• C. C$_3$H$_5$O$_3$
• D. C$_3$H$_5$O$_3$

Hint:

To find molecular formula, first calculate the ratio of atoms using given data and then multiply the empirical formula accordingly.

Answer 1

The Correct Option is B

Step 1: Find the number of moles of hydrogen present. Given mass of hydrogen = 1 g Moles of hydrogen $= \dfrac{1}{1} = 1$ mole
Step 2: Calculate the number of hydrogen atoms per mole of compound. \[ \text{Hydrogen atoms per mole of compound} = \frac{1}{0.0835} \approx 12 \]
Step 3: The empirical formula CH$_2$O contains 2 hydrogen atoms.
Step 4: Determine the multiplication factor: \[ \text{Factor} = \frac{12}{2} = 6 \]
Step 5: Multiply the empirical formula by 6: \[ (\text{CH}_2\text{O}) \times 6 = \text{C}_6\text{H}_{12}\text{O}_6 \]
Step 6: Option (B) represents the molecular formula C$_6$H$_{12$O$_6$}.