WAEC - Chemistry (1994 - No. 20)
Mg\(_2\) + 2HCI\(_{(aq)}\) → MgCI\(_{2(g)}\) + H\(_{2(g)}\).
From the equation above what mass of hydrogen would be produced if 12.0 g of magnesium reacted completely with dilute hydrochloric acid? (H = 1, Mg = 24)
1.0g
2.0g
6.0g
12.0g
24.0g
Explicació
Mg\(_2\) + 2HCI\(_{(aq)}\) → MgCI\(_{2(g)}\) + H\(_{2(g)}\).
24g Mg reacts with 2g H
1g Mg = \(\frac{2}{24}\)g H
12g Mg = \(\frac{2}{24} \times 12\)g H
= 1g H.