Question

What is the mass of $ 0.5 $ mole of oxygen atoms?

• A. $ 10 \, \text{g} $
• B. $ 12 \, \text{g} $
• C. $ 14 \, \text{g} $
• D. $ 8 \, \text{g} $

Hint:

To find the mass of a given number of moles of an element, multiply the number of moles by the molar mass of the element. Always ensure you use the correct atomic mass from the periodic table.

Answer 1

The Correct Option is D

Step 1: Understand the Problem.
The atomic mass of oxygen ($ \text{O} $) is approximately $ 16.00 \, \text{g/mol} $. To find the mass of $ 0.5 $ moles of oxygen atoms, use the formula: \[ \text{Mass} = \text{Number of moles} \times \text{Molar mass}. \] Step 2: Calculate the Mass.
Substitute the given values: \[ \text{Mass} = 0.5 \, \text{mol} \times 16.00 \, \text{g/mol} = 8.00 \, \text{g}. \] Step 3: Analyze the Options.
Option (1): $ 10 \, \text{g} $ — Incorrect, as the calculated mass is $ 8.00 \, \text{g} $.
Option (2): $ 12 \, \text{g} $ — Incorrect, as the calculated mass is $ 8.00 \, \text{g} $.
Option (3): $ 14 \, \text{g} $ — Incorrect, as the calculated mass is $ 8.00 \, \text{g} $.
Option (4): $ 8 \, \text{g} $ — Correct, as it matches the calculated value. Step 4: Final Answer. \[ \boxed{(4) \quad 8 \, \text{g}} \]