1 mol = 32g O2 masa molara O2=2*16=32g/mol
1/4 moli = x g O2 x = 8 g O2
1 mol = 62 g Na2O masa molara Na2O=2*23+16=62g/mol
0.5 moli = x g Na2O x = 31 g Na2O
1 mol = 40 g MgO masa molara MgO=24+16=40g/mol
2,5 moli =x g MgO x = 100 g MgO
1 kmol = 98 kg H2SO4 masa molara H2SO4=2+32+4*16=98g/mol
0,04 kmoli = x kg H2SO4 x = 3.92 kg H2SO4