Zad 1.
2Cu + H₂S → Cu₂S + H₂
2mole --------- 1mol
x moli---------- 9moli
x= 9×2÷1=18 moli (Cu)
Zad 2.
2Mg + O₂-----2MgO
2mole-- 1mol
2×24g ---- 32g
48g:32g /÷16g
3:2 => st. masowy
3. Ile moli sodu potrzeba do 5 moli siarczku sodu Na2S?
2Na + H₂S → Na₂S + H₂
2mole --------- 1mol
xmoli----------- 5 moli
x = 2×5÷1= 10moli (Na)