Răspuns:
Explicație:
1.
2H2 + O2= 2 H2O
H2O + CO2 ⇄ H2CO3
Mg +2 H2O= Mg(OH)2 + H2
2Al + Fe2O3 = Al2O3 + 2Fe
AlCl3 + 3NaOH= Al(OH)3 +3 NaCl
CaCO3= CaO + CO2
2.
15moli Cl2
react. cu Al
masa de AlCl3
15moli xmoli
2Al + 3Cl2 = 2Al Cl3
3moli 2moli
x= 15 . 2 : 3 = 10 moli AlCl3
m= n. M
MAlCl3 = 27 +3.35,5 =133,5------> 133,5g/moli
m= 10moli . 133,5g/moli = 1335 g AlCl3
3.
144g Mg
react. cu O2
masa de MgO
144g xg
2Mg + O2= 2 MgO
2.24g 2. 40g
x= 144 . 80 : 48 =240 g MgO
n= 240g : 40g/moli= 6moli MgO
MMgO= 24 + 16=40------> 40g/moli
4.
1,25g Na , p= 92%
a. ec. react.
b. masa de NaCl
=se afla mp de Na
mp= p . mi : 100
mp= 92 . 1,25 : 100= 1,15 g Na pur
1,15g xg
2Na + Cl2= 2 NaCl
2.23g 2. 58,5g
x= 1,15 . 2 . 58,5 : 2 . 23 =2,925 g NaCl
n= 2,925g : 58,5g/moli=0,05moli NaCl
5.
CaO SO2
M =40 + 16=56-----> 56g/moli
56g CaO---------16g O
100g-------------------x
x= 100.16 : 56= 28,57 % O
MSO2= 32 + 2.16= 64------> 64g/moli
64g SO2------32g O
100--------------------y
y= 100.32 : 64= 50%
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