Question

15 gm of urea and 20gm of naoh dissolved in water total mass of solution is 250 gm .mole mole fraction of naoh in the mixture

Answer 1

Moles of urea (n1) = 15 g / (60 g/mol) = 0.25 mol
Moles of NaOH (n2) = 20 g / (40 g/mol) = 0.5 mol
Moles of water (n3) = (250 - (15 + 20) g) / 18 g/mol = 11.94 mol

Mole fraction of NaOH
= n2 / (n1 + n2 + n3)
= 0.5 / (0.25 + 0.5 + 11.94)
= 0.0394

Mole fraction of NaOH is 0.0394

Answer 2

the right answer is 0.036 . i hope