N2O5, CO2, BeO, MgO, K2O
SiO2, B2O3, BeO, CaO, Li2O
25,8% - 16 г
100% = 62г
62 гр - 16 (О) = 46 :2 = 23
Ответ: Na
Н2SO4 +Na2CO3=H2O+CO2+Na2SO4
1. 2Zn + O2 = 2ZnO
2. ZnO + 2HCl = ZnCl2 + H2O
3. ZnCl2 + 2NaOH = Zn(OH)2 (осадок) + 2NaCl
t
<span>4. Zn(OH)2 = ZnO + H2O</span>