Дано:
m(Pb(NO3)2=132.4
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m(PbS)=?
Na2S+Pb(NO3)2=PbS+2NaNO3
1 моль------1 моль
n(Pb(NO3)2=132.4/331=0.4 моль=n(PbS)
Mr(Pb(NO3)2)=331
Mr(PbS)=239
m(PbS)=239*0.4=95.6 г
2)
Дано:
m(H2SO4)=50 г
w(H2SO4)=14.7\%
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V(H2)-?
m(H2SO4)=50*0.147=7.35 г
n(H2SO4)=7.35:98=0.08 моль=n(H2)
Mr(H2SO4)=98
Mg+H2SO4=MgSO4+H2
1 моль---------------1 моль
V(H2)=22.4*0.08=1.68 л
ZnS+2HCl --> ZnCl2+H2S
2H2S + 3O2 --> 2H2O + 2SO2
2SO2 + O2 --> 2SO3
SO3+H2O-->H2SO4
3H2SO4 + 2Cr(OH)3 --> Cr2(SO4)3 + 6H2O
22.4 дм3
V=Vm*n =>
n=m/M=14/14=1 моль
V=22.4*1=22.4
2Na+2H2O=2NaOH +H2
4K +O2=2K2O