Question

5 probleme la chimie clasa a 8 a inventate si rezolvate rapid va rog!!

Answer 1

1)ms=200 g
md=20 g
concentrata procentuala=?
rezolvare:c/100=md/ms
c=100*20/200
c=10 la suta g
2)compozitia procentuala
36g H2S.... 2g H... 34 g S
100g H2S... x g H... y g S
x=100*2/36=5,5 la suta g Hidrogen
y=100*34/36=9.4 la suta g Sulf
3)H2=?
ms=20 g HCl
c=36,5 la suta
Zn+2HCl=ZnCl2+H2
c/100=md/ms
md=36.5*20/100=7,3 g HCl
M ZnCl2=1*65+2*35,5=65+71=136
x=2*7,3/72=0,2 g H2
4)Fe +H2SO4 =FeSO4+H2
m=?g H2
ms=20 g H2SO4
c=40,5 la suta
md=40,5*20/100=8,1 g H2SO4
x=2*2/98=0,04 g H2
Numai patru am putut face!