a)
1mol apa........18g.........2g H
........................36g........ x=4g H
b)
1 mol NaOH.........40g..........1gH
2 moli...................................x=2gH
c)0,1kmoli=100moli
.....1mol H2SO4........98g..........2gH
100moli H2SO4....................x=200gH