Question

Ma poate ajuta si pe mine cineva la 3 si la 4 va rog !!!!e urgent

Answer 1

III. a) MSO3=32+16*3=80g/mol
nr moli(niu)=m/M=0.8/80=0.01 moli SO3
b)nr molecule=nr moli*NA(nr lui Avogadro)=0.6*6.022*10^23=3.6132*10^23=361.32*10^21 molecule NH3
c)MK2Cr2O7=2*39+2*52+7*16=294g/mol
1 mol K2Cr2O7.....294g K2Cr2O7
4 moli..............xg
x=294*4=1176g K2Cr2O7(bicromat de potasiu)
d)MCuSO4=64+32+16*6=160g/mol
%Cu=mCu/M*100=40/160*100=25
%S=mS/M*100=32/160*100=20
%O=55
e)raport de masa Fe3O4=3*56g:4*16g=168g:64g
IV. 1s2/2s22p6/3s23p4 => perioada 3 si grupa 6,valenta 2
Z=16, Oxigen