Question

2al(s)+3cl2(g)→2alcl3(s) δh∘ = -1408.4 kj. how much heat (in kilojoules) is released on reaction of 4.70 g of al?

Answer 1

Answer:
- 122.58 kJ

Solution:
According to following equation,

2 Al + 3 Cl₂ → 2 AlCl₃ δH° = -1408.4 kJ

When,
54 g (2 mole) Al on reaction releases = 1408.4 kJ heat
So,
4.70 g of Al will release = X kJ of Heat

Solving for X,
X = (4.70 g × 1408.4 kJ) ÷ 54 g

X = - 122.58 kJ