Determine the entropy change for the following displacement reaction. Cl2(g) + PbBr2(aq) → PbCl2(aq) + Br2(l).
DS: (J/K mol)
Cl2(g) 223.066; PbBr2(aq) 182.7; PbCl2(aq) 131.3; Br2(l) 152.231
To determine the entropy change (ΔS) for the displacement reaction, we can use the formula:
ΔS = ΣnΔS(products) - ΣnΔS(reactants)
where Σn represents the stoichiometric coefficient of each species.
Let's calculate the ΔS for the given reaction:
ΔS = (ΣnΔS(products)) - (ΣnΔS(reactants))
ΔS = (1ΔS(PbCl2) + 1ΔS(Br2)) - (1ΔS(Cl2) + 1ΔS(PbBr2))
Now, substitute the given values:
ΔS = (1 * 131.3 J/K mol + 1 * 152.231 J/K mol) - (1 * 223.066 J/K mol + 1 * 182.7 J/K mol)
Calculate the values:
ΔS = (131.3 J/K mol + 152.231 J/K mol) - (223.066 J/K mol + 182.7 J/K mol)
ΔS = 283.531 J/K mol - 405.766 J/K mol
ΔS = -122.235 J/K mol
Therefore, the entropy change for the given displacement reaction is -122.235 J/K mol.
To determine the entropy change (ΔS) for the given reaction, you need to calculate the difference between the sum of entropy values of the products and the sum of entropy values of the reactants. Here's how you can do it step by step:
1. Start by writing down the balanced chemical equation for the reaction:
Cl2(g) + PbBr2(aq) → PbCl2(aq) + Br2(l)
2. Determine the entropy change for each species involved in the reaction using the provided values:
ΔS(Cl2) = 223.066 J/K mol
ΔS(PbBr2) = 182.7 J/K mol
ΔS(PbCl2) = 131.3 J/K mol
ΔS(Br2) = 152.231 J/K mol
3. Calculate the sum of the reactants' entropies:
Sum of entropy of reactants = ΔS(Cl2) + ΔS(PbBr2)
4. Calculate the sum of the products' entropies:
Sum of entropy of products = ΔS(PbCl2) + ΔS(Br2)
5. Finally, calculate the entropy change (ΔS) by subtracting the sum of reactants' entropies from the sum of products' entropies:
ΔS = Sum of entropy of products - Sum of entropy of reactants
Plug in the values:
ΔS = (ΔS(PbCl2) + ΔS(Br2)) - (ΔS(Cl2) + ΔS(PbBr2))
Substitute the given values:
ΔS = (131.3 J/K mol + 152.231 J/K mol) - (223.066 J/K mol + 182.7 J/K mol)
Calculate the value to find the entropy change (ΔS).
DSrxn = (DSproducts)-(DSreactants).
Just plug in the numbers and calculate.