How many molecules of N₂ gas can be present in a 2.5 L flask at 50°C and 650 mmHg?
A. 2.1 × 10⁻²³ molecules
B. 4.9 x 10²² molecules
C. 3.1 x 10²³ molecules
D. 3.6 x 10²⁵ molecules
E. 0.081 molecules