1)<span>2Cr+O2=2CrO
2)---------------------
3)</span><span>Cr2(SO4)3+6KOH=2Cr(OH)3+3K2SO4
4)</span><span>Cr(OH)3 + 3HNO3(разб. ) = Cr(NO3)3 + 3H2O
5) </span><span>Cr(OH)3 + 3 NaOH = Na3CrO3 + 3 H2O
==========================================
</span>1)2Ca+O2=2CaO
<span>2)CaO+H2O=Ca(OH)2
3)</span>Ca(OH)2=CaO+H2O
4)CaO+CO2=<span>CaCO3
5)</span><span>CaCO3+CO2+H2O=Ca(HCO3)2
6)</span><span>Ca(hco3)2=Caco3+co2+h2o
7)</span><span>Caco3=Cao+Co2</span>
Дано:
m (NaOH) = 30г
Найти:
m (CH3COOH) - ?
Решение:
CH3COOH + NaOH = CH3COONa + H2O
n (NaOH) = m/M = 30 / 40 = 0.75 моль
n (CH3COOH) = n (NaOH) = 0.75 моль (по уравнению)
m (CH3COOH) = n * M = 0.75 * 60 = 45г
Ответ: m (CH3COOH) = 45г
M(HCOOH)=46 а.е.м.
A(O)=16 а.е.м.
w(O)=2A(O)/M(HCOOH)
w(O)=2*16/46=0,696
Дано: Решение: m=n*M
n(H2O)= 6 моль M(H2O)=1*2+16=18 г/моль
__________________ m(H2O)= 6моль * 18г/моль= 108г
m-? Ответ: 108г