Question

Fraksi mol urea dalam larutn yg dibuat dgn melarutkn 30 gr urea (Mr=60) ke dlm 0,09kg air(Mr=18) ?

A ½
B 1/10
C 1/11
D 1/5
E 5

Answer 1

Verified answer

Mol = massa/Mr

mol urea = 30/60 = 1/2 mol

mol air = 90/18 = 5

Xt = nt / nt + np

   = (1/2) / (1/2) + 5 = (1/2) / 11/2 =1/11

Answer 2

Mol urea = gr/Mr = 30/60
= 0.5
Mol air = gr/Mr = (0.09×1000)/18
= 5
Fraksi mol = mol urea/mol campuran
= 0.5/0.5+5
= 0.090 = 1/11 ( C )