Verified answer

Masa molar NH3 = 14+1x3 = 17g/mol

densidad del agua = 1g/mL --> 70g = 70mL

Molaridad:

M = masa / (PM x V)

M = 30g / (17g/mol x 0.07L)

M = 25.21 mol/L o Molar

Normalidad:

N = f x M

f = 1 (amoniaco tiene la capacidad de captar un proton como base)

N = 1 x 25.21 Molar

N = 25.21 Normal

Fraccion molar

MM H2O = 1x2 + 16 = 18g/mol

mol = masa / PM = 70g / 18g/mol = 3.89 moles

moles totales = 25.21 mol + 3.89 mol = 29.1 mol

fraccion molar NH3 = 25.21 mol / 29.1 mol = 0.87