Question

The number of moles of ammonia that have the same mass as that of 3 moles of carbon dioxide is
(1) 0.19 mol
(2) 2.58 mol
(3) 9.04 mol
(4) 7.76 mol

Answer 1

The correct answer is option 4 - 7.76 mol.

1 mole of carbon dioxide CO₂ = 12 (C) + 32 (O₂) = 44 g

Therefore, mass of 3 moles of CO₂ = 3 x 44 = 132 g

Molar mass of ammonia NH₃ = 17 g

No. of moles = given weight/molar mass

Therefore, no. of moles of NH₃ = 132/17 = 7.76

Thus, 7.76 moles of ammonia have the same mass as that of 3 moles of carbon dioxide.