Dopamine is a neurotransmitter, a molecule that serves to transmit message in the brain. The chemical formula of dopamine is `C_(8)H_(11)O_(2)N.` How many moles of oxygen atoms are present in 76.5 gm of Dopamine :-

Options

A. 1 mole
B. `0.5` mole
C. 2 mole
D. 3 mole

Answer

To find the number of moles of oxygen atoms present in 76.5 grams of dopamine (C₈H₁₁O₂N), we will follow these steps:

### Step 1: Determine the molecular mass of dopamine.
The molecular formula of dopamine is C₈H₁₁O₂N. We need to calculate its molar mass by adding the atomic masses of all the atoms in the formula.

- Carbon (C): 12.01 g/mol × 8 = 96.08 g/mol
- Hydrogen (H): 1.008 g/mol × 11 = 11.088 g/mol
- Oxygen (O): 16.00 g/mol × 2 = 32.00 g/mol
- Nitrogen (N): 14.01 g/mol × 1 = 14.01 g/mol

Now, summing these values:
\[ \text{Molar mass of dopamine} = 96.08 + 11.088 + 32.00 + 14.01 = 153.178 \text{ g/mol} \]
For practical purposes, we can round this to 153 g/mol.

### Step 2: Calculate the number of moles of dopamine in 76.5 grams.
Using the formula for moles:
\[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} \]
Substituting the values:
\[ \text{Number of moles of dopamine} = \frac{76.5 \text{ g}}{153 \text{ g/mol}} \approx 0.5 \text{ moles} \]

### Step 3: Determine the number of moles of oxygen atoms.
From the molecular formula C₈H₁₁O₂N, we see that each mole of dopamine contains 2 moles of oxygen atoms. Therefore, if we have 0.5 moles of dopamine, the number of moles of oxygen atoms can be calculated as follows:
\[ \text{Number of moles of oxygen} = 0.5 \text{ moles of dopamine} \times 2 \text{ moles of O} = 1 \text{ mole of O} \]

### Final Answer:
Thus, the number of moles of oxygen atoms present in 76.5 grams of dopamine is **1 mole**.

---