Question

Find the volume of 56 g dinitrogen at STP.

• A. 11.2 Lit.
• B. 22.4 Lit.
• C. 44.8 Lit.
• D. 67.2 Lit.

Hint:

Do not get confused by the term "dinitrogen". It is simply the formal IUPAC name for standard nitrogen gas ($N_2$), emphasizing its diatomic nature so you use 28 g/mol instead of 14 g/mol.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the volume occupied by a specific mass (56 g) of nitrogen gas ($N_2$) at Standard Temperature and Pressure (STP).

Step 2: Key Formula or Approach:
We use two basic mole concepts:
1. $\text{Moles (n)} = \frac{\text{Given Mass}}{\text{Molar Mass}}$
2. At STP, 1 mole of any ideal gas occupies exactly 22.4 Liters (molar volume).
Therefore, $\text{Volume} = \text{Moles} \times 22.4 \text{ L}$.

Step 3: Detailed Explanation:
First, identify the gas. "Dinitrogen" means diatomic nitrogen gas ($N_2$).
Atomic mass of Nitrogen (N) = 14 g/mol.
Molar mass of $N_2$ = $2 \times 14 = 28 \text{ g/mol}$.
Calculate the number of moles present in 56 g:
$$n = \frac{56 \text{ g}}{28 \text{ g/mol}} = 2 \text{ moles}$$
Calculate the total volume at STP:
$$\text{Volume} = 2 \text{ moles} \times 22.4 \text{ L/mol}$$
$$\text{Volume} = 44.8 \text{ Lit.}$$

Step 4: Final Answer:
The volume is 44.8 Lit., matching option (c).