CaCO3 = CaO + CO2
n(СaO) = m/M = 32г/56(г/моль)= 0,57моль
n(CaO) = n(CaCO3)
m(CaCO3) (чистый) = n*M = 0,57моль*100(г/моль) = 57г
w(CaCO3) = 57г/60г*100\% = 95\%
Ответ: 95\%
4,1)FeCl3 + Na3PO4 = 3NaCl + FePO4
Fe(3+) + PO4(3-) = FePO4
4.2) Cu(NO3)2 + 2KOH = 2KNO3 + Cu(OH)2
Cu(2+) + 2OH(-) = Cu(OH)2
5.1) Na2SO4 + HCl = не идет
5.2) Cu(NO3)2 + 2KOH = 2KNO3 + Cu(OH)2
Cu(2+) + 2OH(-) = Cu(OH)2
5.3) CaCO3 + H2SO4 = CaSO4 + CO2 + H2O
<span>2H(+) + SO4(2−) + CaCO3 = CaSO4↓ + CO2 + H2<span>O</span></span>
М Na = 2.3г
Mр-ра = 11,5г
Омега ( W) = M р.в \ М р-ра = 2.3 : 11,5 = 0,2 или 20%
<span>6K + N2 ---> 2K3N</span>
3Ba + 2O2 ---> 2BaO + BaO2
<span>2Al + 3NiSO4 ---> 3Ni +Al2(SO4)3
</span>
<span><span>BaO + 2HCl (разб.) ---> BaCl</span>2<span> + H</span>2<span>O </span></span>
<span><span>BaO + 2Н(+) + 2Сl(-) ----> Ba(2+)+ 2Cl(-) + H2O </span></span>
<span><span><span>3Ba(OH)2 + 2AlCl3 ---> 2Al(OH)3 + 3BaCl2
</span></span></span>
<span><span><span><span>3KOH+ CrCl3 + ---> Cr(OH)3↓ + 3KCl</span></span></span></span>
<span><span><span><span>3K (+) + 3OH(-) + Cr (3+) + 3Cl(-) ---> Cr(OH)3↓ + 3K (+)+ 3Cl(-)</span></span></span></span>
<span><span><span><span> 3OH(-) + Cr (3+)---> Cr(OH)3↓</span></span></span></span>
<span><span><span><span><span>Al</span>2<span>O</span>3<span> + 2NaOH ---> 2NaAlO</span>2<span> + H</span>2<span>O (при сплавлении)</span></span></span></span></span>
<span><span><span><span><span><span>2Al(ОН)3+3H2SO4 = Al2(SO4)3+6H2O
</span></span></span></span></span></span>