What will be the mass of `O_2` molecule in grams?

Options

A. `5.31X10^-23` g
B. `32 g`
C. `16 g`
D. `2.6X10^-23` g

Answer

To find the mass of an \( O_2 \) molecule in grams, we will follow these steps:

### Step 1: Determine the atomic mass of oxygen
The atomic mass of a single oxygen atom (O) is approximately 16 atomic mass units (AMU).

### Step 2: Calculate the molecular mass of \( O_2 \)
Since \( O_2 \) consists of two oxygen atoms, we multiply the atomic mass of oxygen by 2:
\[ \text{Molecular mass of } O_2 = 16 \, \text{AMU} \times 2 = 32 \, \text{AMU} \]

### Step 3: Convert the molecular mass from AMU to grams
To convert the mass from AMU to grams, we use the conversion factor:
\[ 1 \, \text{AMU} = 1.66 \times 10^{-24} \, \text{grams} \]
Now, we can convert the molecular mass of \( O_2 \):
\[ \text{Mass of } O_2 \text{ in grams} = 32 \, \text{AMU} \times 1.66 \times 10^{-24} \, \text{grams/AMU} \]

### Step 4: Perform the multiplication
Calculating the above expression:
\[ 32 \times 1.66 \times 10^{-24} = 53.12 \times 10^{-24} \, \text{grams} \]

### Step 5: Adjust the decimal point
To express this in standard scientific notation:
\[ 53.12 \times 10^{-24} \, \text{grams} = 5.312 \times 10^{-23} \, \text{grams} \]

### Final Answer
The mass of an \( O_2 \) molecule is:
\[ \text{Mass of } O_2 = 5.312 \times 10^{-23} \, \text{grams} \]

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