a sample of dinitrogen tetroxide (N2O4) gas occupies 144 L at STP. how many moles of nitrogen atoms are present in this sample? __ moles
Answer (1)
Answer:Rounding to 3 significant figures, the number of moles of nitrogen atoms that's why answer is $n_{\text{N}} \approx {12.9 \text{ moles}}.$Solve:Solve the moles of nitrogen atoms problem again, using standard scientific variables for clarity in the calculation.$V = 144 \text{ L}$ (Volume of $\text{N}_2\text{O}_4$ gas at STP) $V_m = 22.4 \frac{\text{L}}{\text{mol}}$ (Molar volume at STP) Find the moles of $\text{N}_2\text{O}_4$ gas ($n_{\text{N}_2\text{O}_4}$):$n_{\text{N}_2\text{O}_4} = \frac{V}{V_m}$$n_{\text{N}_2\text{O}_4} = \frac{144 \text{ L}}{22.4 \frac{\text{L}}{\text{mol}}}$$n_{\text{N}_2\text{O}_4} \approx 6.42857 \text{ mol}$Next, find the moles of nitrogen atoms ($n_{\text{N}}$). From the formula $\text{N}_2\text{O}_4$, there are 2 moles of N atoms for every 1 mole of $\text{N}_2\text{O}_4.$$n_{\text{N}} = 2 \times n_{\text{N}_2\text{O}_4}$$n_{\text{N}} \approx 2 \times 6.42857 \text{ mol}$$n_{\text{N}} \approx 12.85714 \text{ mol}$[tex] \: [/tex]
