M(Cr2O3)=52*2+16*3= 152 g/mol
W(Cr)=Ar(Cr)*n / M(Cr2O3)*100% = 52*2 / 152*100%=68.42%
W(O) = 100%-W(Cr)=100-68.42=31.58%
M(ZnCO3)=65+12+16*3=125g/mol
W(Zn)=65/125*100%=52 %
W(C)=12/125*100% = 9.6%
W(O)=16*3 / 125 *100%=38.4 %
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1) 2KMnO4 + 16HCl = 2KCl + 2MnCl2 + 5Cl2 + 8H2O
2) Это невозможно
3) 4Fe(OH)2 + O2 + 2H2O = 4Fe(OH)3
4) Hg + 4HNO3 = Hg(NO3)2 + 2NO2 + 2H2O
5) 2Al + 3H2SO4 = Al2(SO4)3 + 3H2
C4H10=(кат. AlCl3)=H3C-CH(CH3)-CH3
H3C-CH(CH3)-CH3+Br2 = H3C-CBr(CH3)-CH3
H3C-CBr(CH3)-CH3+H2 =(кат)= H3C-CH(CH3)-CH3
H3C-CH(CH3)-CH3 =(t,кат)= H2C=C(Ch3)-Ch3
H2C=C(Ch3)-Ch3 + h2o = H3C-C(Oh)(Ch3)-Ch3
C + O2 = CO2
CO2 + Ca(OH)2 = CaCO3 + H2O<span>
CO2 + 2NaOH = Na2CO3 + H2O
</span><span>Na2CO3 -->(t*) Na2O + CO2</span><span>
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