Question

URGENT! +COROANA
Exercitiul 1
50g sare bucatarie
20g solutie sare
c=20%
c solutie=?
Exercitiul 2:
300g apa
800g solutie alcool
c=15%
20g alcool pur
c solutia finala=?

Answer 1

textul lipseste si e cam greu ca cineva sa-l ghiceasca
1.din ms=20g si c=20%, calculez md
20/100= md/20---> md= 4g
Se adauga 50g sare ??????
c/100= (4+50)/(20+50)--------------------calculeaza    c !!!

din ms=800g si c=15%,calculez md
15/100=md/800---> md= 120g
probabil ca se adauga 300g apa si  20g alcool ??????

c,final/100= (120+20)/ (800+20+300)= --------------------calculeaza c !!!!