During estimation of nitrogen by Dumas' method of compound X (0.42 g) [figure] mL of N2 gas will be liberated at STP. (nearest integer) (Given molar mass in g mol-1 : C : 12, H : 1, N : 14)
Answer
109
Solution
Compound X is piperazine, C4H10N2.
Molar mass = 4 12 + 10 1 + 2 14 = 86 g mol-1
Moles of X = 0.4286 = 4.884 10-3 mol
∵ 1 mol of C4H10N2 contains 2 mol N atoms, it gives 1 mol N2
⇒ Moles of N2 = 4.884 10-3 mol
∴ Volume of N2 at STP = 4.884 10-3 22400
= 109.4 mL 109 mL
Answer: 109