Answer:
Option B
Explanation:
280g of $N_{2}$=$\frac{280}{28}=10 $ moles of $N_{2}$
$27^{0} C= (27+273)K=300K$
K.E = $ \frac{3nRT}{2}$ = 3 x number of mol x 3 x moles of gas x gas constant x temperature /2
= $\frac{3 \times 10 \times 8.314 \times 300}{2}=37.4 \times 10^{3} J$=37.4 kJ