The standard internal energy change for a reaction can be symbolized as ΔU°rxn or ΔE°rxn.

For the following reaction equations, calculate the energy change of the reaction at 25 °C and 1.00 bar.

Sn(s) + 2Cl2(g) --> SnCl4(l)
ΔH°rxn = -511.3 kJ/mol
ΔU°rxn = -506.3

H2(g) + Cl2(g) --> 2HCl(g)
ΔH°rxn = -184.6 kJ/mol
ΔU°rxn = ?

I know ΔU°rxn = q + work
q = ΔH°rxn

How do I find work for the second reaction?

thog

Avery is correct

Since the number of moles of the reactants is 1+1 and the number of moles of the product is 2, they are equal which means that the change in the number of moles is zero. This means that ΔU°rxn is going to be equal to ΔH°rxn. ΔU°rxn= -184.6

The standard internal energy change for a reaction can be symbolized as Δ𝑈∘rxn or Δ𝐸∘rxn . For each reaction equation, calculate the energy change of the reaction at 21 ∘C and 1.00 bar .

2H2(g)+O2(g)⟶2H2O(l)Δ𝐻∘rxn=−561.2 kJ/mol

Well, finding work for the second reaction might require a bit of creativity. You could try hiring some math-savvy circus clowns to perform some tricks involving gas expansion or compression, and then calculate the work based on their impressive circus acts. But, unfortunately, that might not be the most practical option.

In this case, since the reaction involves gases, you can assume that the only type of work being done is pressure-volume work. In other words, work = -PΔV.

Since you're dealing with gases here, you can use the ideal gas law, PV = nRT, to calculate the change in volume (∆V). However, for this reaction, the number of moles doesn't change, so the change in volume (∆V) will be zero.

Therefore, work = -P(∆V) = -0 = 0 J.

So, the work for the second reaction is zero. But keep in mind that in the real world, the circus clowns might have provided a much more entertaining and memorable answer.

To find the work for the second reaction, you can use the equation:

work = -PΔV

Where P is the pressure and ΔV is the change in volume.

In this case, the reaction is happening at a constant pressure of 1.00 bar, so the pressure is known. However, we don't know the change in volume directly. To find the change in volume, we need to determine the stoichiometry of the reaction and the number of moles of gases involved.

The balanced equation for the reaction is:

H2(g) + Cl2(g) --> 2HCl(g)

From this equation, we can see that two moles of gas are converted to two moles of gas. Since the number of moles before and after the reaction is the same, there is no change in volume (ΔV = 0).

Therefore, the work in this case is zero, because there is no change in the volume of the gases involved.

So, for the second reaction, ΔU°rxn = ΔH°rxn = -184.6 kJ/mol.