65.5k views
3 votes
Determine the value of heat of reaction for the following? Cl(g) + O3(g) yield ClO(g) + O2(g)

2 Answers

6 votes

Final answer:

The value of the heat of reaction for the given reaction Cl(g) + O3(g) -> ClO(g) + O2(g) can be determined using Hess's law. By adding the enthalpy changes of two known reactions, we can calculate the enthalpy change of the desired reaction.

Step-by-step explanation:

The value of the heat of reaction for the given reaction Cl(g) + O3(g) → ClO(g) + O2(g) can be determined using Hess's law.

We can use the enthalpy changes of known reactions to calculate the enthalpy change of the desired reaction. By adding together the enthalpy changes of two other reactions, we can obtain the desired reaction equation.

In this case, we can use the following known reactions:

  1. Cl2(g) + O2(g) → 2 ClO(g) (enthalpy change = -236.2 kJ)
  2. Cl2(g) + 3/2 O2(g) → ClO(g) + O2(g) (enthalpy change = 107.0 kJ)

By adding these two reactions together, we get the desired reaction equation. We can also add their enthalpy changes to determine the heat of reaction for the given reaction:

Heat of reaction = -236.2 kJ + 107.0 kJ = -129.2 kJ

User Bluefire
by
6.7k points
2 votes
The final reaction needs to have ClO on the product side of the equation. We have to reverse the first equation, which will also change the sign of dH. (+122.8 kj/mol)

The next equation can remain as is because our final step calls for O2 as a product which we already have. Making dH: (-285.3 kj/mol)

Add them: +122.8 kj/mol + (-285.3 kj/mol)= -162.5 kj/mol
User Wesley Petrowski
by
7.0k points