Which of the following has highest mass?

Options

A. One gram atom of Iron
B. 5 moles of `N_(2)`
C. `10^(24)` carbon atoms
D. 44.8 lit of He at STP

Answer

To determine which of the following options has the highest mass, we will calculate the mass for each option provided.

### Step-by-Step Solution:

1. **Calculate the mass of 1 gram atom of iron:**
- The atomic mass of iron (Fe) is 56 g/mol.
- Since 1 gram atom of iron is equivalent to 1 mole, the mass is:
\[ \text{Mass of 1 gram atom of Fe} = 56 \text{ g} \]

2. **Calculate the mass of 5 moles of nitrogen:**
- The molecular mass of nitrogen (N₂) is calculated as:
\[ \text{Molecular mass of N₂} = 2 \times 14 \text{ g/mol} = 28 \text{ g/mol} \]
- Therefore, the mass of 5 moles of nitrogen is:
\[ \text{Mass of 5 moles of N₂} = 5 \times 28 \text{ g} = 140 \text{ g} \]

3. **Calculate the mass of \(10^{24}\) carbon atoms:**
- The atomic mass of carbon (C) is 12 g/mol.
- One mole of carbon contains \(6.02 \times 10^{23}\) atoms and has a mass of 12 g.
- To find the mass of \(10^{24}\) carbon atoms:
\[ \text{Mass of } 10^{24} \text{ C atoms} = \left(\frac{12 \text{ g}}{6.02 \times 10^{23} \text{ atoms}}\right) \times 10^{24} \text{ atoms} \]
\[ = \frac{12 \times 10^{24}}{6.02 \times 10^{23}} \text{ g} \approx 20 \text{ g} \]

4. **Calculate the mass of 44.8 liters of helium at STP:**
- The atomic mass of helium (He) is 4 g/mol.
- At STP, 22.4 liters of helium has a mass of 4 g.
- Therefore, for 44.8 liters:
\[ \text{Mass of 44.8 L of He} = 2 \times 4 \text{ g} = 8 \text{ g} \]

5. **Compare the masses calculated:**
- Mass of 1 gram atom of iron: **56 g**
- Mass of 5 moles of nitrogen: **140 g**
- Mass of \(10^{24}\) carbon atoms: **20 g**
- Mass of 44.8 liters of helium: **8 g**

### Conclusion:
The option with the highest mass is **5 moles of nitrogen**, which has a mass of **140 g**.

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