When the oxide of generic metal M is heated at 25.0 ∘ C , a negligible amount of M is produced. MO 2 ( s ) − ⇀ ↽ − M ( s ) + O 2 ( g ) Δ G ∘ = 291.0 kJ mol When this reaction is coupled to the conversion of graphite to carbon dioxide, it becomes spontaneous. What is the chemical equation of this coupled process? Show that the reaction is in equilibrium. Include physical states and represent graphite as C ( s ) .

The chemical equation after coupling both reaction :

Explanation:

.....[1]

..[2]

The chemical equation after adding both the reactions :

[1] + [2] :

The chemical equation of this coupled process:

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2