Question

Calcule la molalidad de una solucion que se prepara disolviendo 55g de nacl en 250 ml de solucion

Answer 1

Mm NaCl = 58.45 g/mol

m = mol soluto /Kg solvente

1. calcular moles

n = masa/Mm

n = 55 g / 58.45 g/mol

n = 0.941 moles de NaOH

2. convertir mL a L

L = 250 / 1000 = 0.250 L

0.250 L = 0.520 Kg de solución

3. calcular m

m = 0.941 mol / 0.520 Kg

m = 1.80 molal