а) O N C
б)Rb K NA
в) Br Cl F
с) <span> Be Mg Ca</span>
Ca3(PO4)2+5C+3SiO2 = 3CaSiO3+2P+5CO
<span>С6Н5-COONa
+ NaOH
→ C6H6 + Na2CO3</span>
<span>C6H6→C2H4,H3PO4→C6H5 – CH2-CH3(этилбензол)(X1)
</span> C6H5 – CH2-CH3→Cl,hλ→C6H5-CHCl-CH3(X2)
C6H5-CHCl-CH3
+ C2H5ONa→C6H5-CH=CH2
C6H5-CH=CH2→KMnO4,H2SO4→C6H5-COOH
(X3)
BeF2 + 2KOH= Be(OH)2 (осадок) + 2KF