Răspuns:
495,555g PbO
Explicație:
m pur 650
PbO + 2CH3-COOH -----> (CH3-COO)2Pb + H2O
223 325
m (CH3-COO)2Pb=650g
Calculam masele molare/moleculare
M (CH3-COO)2Pb = 325 g/mol
M PbO = 223 g/mol
De pe reactie obtinem ca:
[tex]m \ pur= \frac{223*650}{325} = 446 g[/tex]
[tex]puritatea=\frac{m \ pura \ * \ 100}{m \ impura}[/tex]
Noi cautam masa de PbO necesara, deci masa impura
[tex]90=\frac{446*100}{mPbO} = > m PbO=\frac{446*100}{90} = 495,555 g[/tex]
