Răspuns:
Explicație:
7. c , d
c
c MKOH 39 _ 16 + 1=56-------> 56g/moli
56g KOH------39g K
100g----------------x
x= 100. 39 : 56= 69,6 % K
8.
a.
m= n . M
M Ca(OH)2= 40 + 2.16 + 2= 74-------> 74g/moli
m= 3moli . 74g/moli= 222 g Ca(O)H)2
b.
xg 49g
2 Fe(OH)3 + 3H2SO4 = Fe2(SO4)2 + 6 H2O
2 .107g 3.98g
x= 2 . 107 . 49 : 3 . 98 =35,6 g Fe(OH)3
n= 35,6 g : 107=0,3 moli Fe(OH)3
M Fe(OH)3= 56 + 3.16 + 3= 107------> 107g/moli
M H2SO4 =2 + 32 + 4.16= 98-----> 98g/moli
