Question

Calculati volumul de solutie de clorura de fier 3 de xoncentratie 0,5M necesar pt a prepara 250 de mL de solutie de concentratie 0,005M

Answer 1

V2= 250 mL = 0.25 L
C2=0.005 M (mol/L)
C=n/V => n= V x C => n FeCl3 = 0.25 x 0.005 =0.00125 mol FeCl3

V1=?
C1= 0.5 M (mol/L)
n= 0.00125 mol
C= n/V => V= n/C => V FeCl3 = 0.00125 / 0.5 = 0.0025 L =  2.5 mL

sau mai simplu:
C1V1 = C2V2 => V1 = C2V2 / C1 => V1 = 0.005 x 0.25 / 0.5 = 0.0025 = 2.5 mL
C1=0.5 mol/L
V1=?
C2 = 0.005 mol/L
V2 = 0.25 L