1. 82 g H2SO3...............32 g sulf
x g H2SO3...................69 g sulf
=> 32x =69*82 = 5658
=> x = 176.81 g
2. M ZnO = 81
81g ZnO..................65g Zn
3*81 = 243g............x g Zn
x = 65*243/81 = 195 g
3. M CuSO3 = 143 g
143g CuSO3 ..........................63 g Cu
x g CuSO3...............................128 g Cu
=> x = 143*128/63 = 290.53 g CuSO3
Sper ca te-am ajutat !