2 NO(g) + O2(g) = 2 NO2(g)
2 moles NO ------------ 2 moles NO2
2.40 moles NO ---------- ? ( moles NO2)
moles NO2 = 2.40 x 2 / 2
moles NO2 = 4.8 / 2
= 2.4 moles of NO2
molar mass NO2 = 46.0 g/mol
1 mole ----------- 46.0 g
2.4 moles ------- ( mass NO2)
mass NO2 = 2.4 x 46.0 / 1
mass NO2 = 110.4 / 1
= 110.4 g of NO2