Calculam md (pentru solutia initiala):
[tex]md_{i}= \dfrac{c*ms}{100} = \dfrac{5*200}{100}=10 \ g\ NaOH[/tex]
Calculam md final (masa dizolvata in solutia finala):
[tex]md_{f}=md_{i}+m_{adaugata}[/tex]
[tex]md_{f}=10+20=30 \ g \ NaOH[/tex]
Calculam masa solutiei finale:
[tex]ms_{f}=ms_{i}+m_{adaugata}[/tex]
[tex]ms_{f}=200+20=220 \ g [/tex]
Aplicam formula concentratiei procentuale:
[tex]c_{f}= \dfrac{md_{f}*100}{ms_{f}} = \dfrac{30*100}{220}= 13,64 \ \% [/tex]
