Question

PILNE !!!!Ile molo NaOH potrzeba do przygotowania

a)250 g roztworu o stężeniu 6%

b)200g roztw.o stęż. 5%

Answer 1

Odp.

ms=(Cp*mr)/100[%];

a) ms=(250[g]*6[%])/100[%]=15[g]

M(NaOH)=23[g/mol]+17[g/mol]=40[g/mol].

1[mol] NaOH -40[g] NaOH;

x[moli] NaOH - 15[g] NaOH;

x=15/40=0,375[mola] NaOH.

b) ms=(Cp*mr)/100[%];

  ms=(200[g]*5[%])/100[%]=10[g] NaOH.

1[mol] NaOH  -40[g] NaOH;

x [moli] NaOH - 10[g] NaOH.

x=10/40=0,25[mola] NaOH.

Odp. a) 0,375[mola] NaOH; b) 0,25[mola] NaOH