Question

O solutie de concentratie ,c, are masa ,m,.Calculati cantitatea de apa care trebuie adaugata pentru a scadea concentratia de n ori.

Answer 1

cf = c:n
md = (m * c)100
cf = ( md * 100 ) m + m apa
c:n = ( md * 100 ) : m + m apa
n*md*100 = c * m + c*m apa
n * md * 100 - c*m = c * m apa
m apa = ( n * md * 100 - c * m ) : c