What is this balanced?
Al2O3---> Al+O2

The balanced equation :

2Al₂O₃⇒ 4Al+3O₂

Given

Reaction

Al₂O₃⇒ Al+O₂

Required

Balanced equation

Solution

A chemical reaction is said to be balanced if the number of elements involved in the reaction is the same (either the reactants or the products)

The reaction above is said to be unbalanced because the number of elements Al and O in the reactants and products is not the same.

The balancing step

1. Give a coefficient

Al₂O₃⇒ aAl+bO₂

2. Make an equation

Al, left = 2, right = a⇒a=2

O, left = 3, right = 2b⇒2b=3⇒b=3/2

The equation becomes :

Al₂O₃⇒ 2Al+3/2O₂ x2

2Al₂O₃⇒ 4Al+3O₂

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :