Question

which of the following has highest mass? why
a one gram atom of iron
b 5 moles of N₂
c 10²⁴ carbon atoms
d 44.8 lit of He at STP

Answer 1

 5 moles of N₂ has highest mass.

 mass of 1 mole N₂ = 28g
    mass of 5 mole N₂ = 28×5 = 140g

Answer 2

a. Mass of one gram atom of iron = Atomic mass of iron = 55.84 g b. Mass of 5 moles of N₂ = 5 × 28 = 140 g #As, one mole of N₂ weighs 28 g. c. Mass of 10²⁴ carbon atoms = (12 × 10²⁴)/(6 × 10²³) = 20 g #As, 6 × 10²³ carbon atoms weigh 12 g. d. Mass of 44.8 lit. of He at STP = (44.8 × 4)/(22.4) = 8 g #As, 22.4 lit. of He at STP weighs 4 g. Hence, option b is the correct answer. 5 moles of N₂ has the highest mass.