Question

Calculeaza masa moleculara , raportul atomic , raportul de masa si compozitia procentuala pentru:
MgCl2
K2O
Ca(OH)2
H2SO4
Ca3(PO4)2
Va rog mult , e urgent , vreau doar raspunsul nu calculele desfasurate , dau coroana , va rog mult

Answer 1

MgCl2

M=24+2.35,5=95

r.a.=1Mg:2Cl=1:2

r.m.=AMg:2ACl=24:2.35,5=24:71

comp .proc. prin masa moleculara

M=95

95 g MgCl2----------24g Mg--------71g Cl
100 g---------------------x----------------y

x=100.24:95=25,26 la suta Mg

y-100.71:95=74,73 la suta Cl


K2O
M=2.39+16=94
r.a.=2K:1O=2:1
r.m.=2AK:AO=2.39:16=78:16=39:8
Comp. proc.

94gK2O----------78gK---------16g O
100g--------------x------------------y
x=100.78:94=82,97 la suta K
Y=100.16:94=17,02 la suta O


Ca(OH)2

M=40+2.16+2=74
r. a.=1Ca:2O:2H=1:2:2
r.m.=ACa:2AO:2AH=40:2.16:2=40:32:2=20:16:1
Comp. proc.
74g Ca(OH)2-------------40g Ca---------32g O--------2gH
100g----------------------------x------------------y------------z
x=100.40:74=54,05 la suta Ca
y-100.32:74=43,24 la suta O
z=100.2:74=2,70 la suta H


H2SO4
M=98
r.a.=2:1:4
r.m.=2:32:64=1:16:32
98g H2SO4-----------2gH--------32gS---------64 g O
100g-----------------------x-------------y---------------z
x=2,04 la suta H
y=32,65la suta S
z=65,30 la suta O


Ca3(PO4)2
M=3.40+2.31+8.16=310
r.a.=3:2:8
r.m.=3.40:2.31:8.16=120:62:128=60:31:64

310g Ca3(PO4)2--------120g Ca-------------62 g P-------128 g O
100g-----------------------X---------------------------Y------------------Z
X=38,70 la suta Ca
y=20 la suta P
Z=41,29 la suta O