What volume of H2 at NTP is required to convert 2.8g of N2 in to NH3?

N2(g) + 3 H2 (g) → 2 NH3 (g)1 mole      3 moles28 g              67.2 lit2.8 g               ‘ X ’X = 2.8 x 3 22.428= 6.72 lit