Question

Calculati Concentratia Procentuala a solutiei care contine 2,5 moli de hidroxid de sodiu dizolvati in 900 g de apa.

Answer 1

n = m/μ
m = n * μ 
m = 2,5 * 40 (masa molara NaOH) 
=> m = 100 g NaOH
md = 100 g NaOH
ms = md + m apa
ms = 100 + 900
=> ms = 1000 g solutie
c = md/ms * 100 
c = 100/1000 * 100
=> c = 10%