Question

Cuál es el pH de 5,8g de NaOH En 390 ml de solución

Answer 1

Mm NaOH = 40 g/mol

1. calcular la concentracion de NaOH

a) calcular moles

n = masa/Mm

n = 5.8 g/ 40 g/mol

n =  0.145 moles

b) transformar mL a L

L = 390 / 1000 = 0.390 L

c) calcular la Molaridad = moles soluto /V(L)

M = 0.145 moles/ 0.390 L

M = 0.37 molar

2. calcular el pOH = -log []

pOH = -log [0.37]

pOH = -(- 0.43) 0.43

3. calcular pH donde  pH + pOH = 14

pH = 14 - 0.43

pH = 13.57