Răspuns:
M=H3PO4=3x1+31+4x16=98g/mol
m=nxM=3x98=294g H3PO4
98g H3PO4...............64gO
294g H3PO4..............xgO
x=294x64/98=192gO
MCa(OH)2=40+2x16+2x1=74g/mol
m=nxM=3x74=222gCa(OH)3
74g Ca(OH)2................32gO
222g Ca(OH)2................xgO
x=222x32/74=96gO
Explicație: