Which of the following formulas represents an organic compound?

• A. $H_{2}O$
• B. $\mathrm{NaCl}$
• C. $C_2{H}_6$
• D. ${\mathrm{Na}}_2\mathrm{SO}{4}_2$

Answer: (C)

Verified step by step guidance

1. Step 1: Understand what defines an organic compound. Organic compounds primarily contain carbon (C) atoms bonded to hydrogen (H) atoms, and often include other elements like oxygen (O), nitrogen (N), sulfur (S), etc., but the key feature is the presence of carbon-hydrogen bonds.
2. Step 2: Examine each given formula to identify the presence of carbon and hydrogen atoms bonded together. For example, \(\mathrm{H_2O}\) (water) contains hydrogen and oxygen but no carbon, so it is inorganic.
3. Step 3: Look at \(\mathrm{NaCl}\) (sodium chloride), which is an ionic compound made of sodium and chlorine ions, with no carbon or hydrogen, so it is inorganic.
4. Step 4: Consider \(\mathrm{C_2H_6}\) (ethane), which contains carbon and hydrogen atoms bonded together, fitting the definition of an organic compound.
5. Step 5: Analyze \(\mathrm{Na_2SO_4}\) (sodium sulfate), which contains sodium, sulfur, and oxygen but no carbon, so it is inorganic.