Question 19.3: Calculating ΔS° for a Reaction Calculate the change of entro...

Calculating $\Delta S^{\circ}$ for a Reaction

Calculate the change of entropy, $\Delta S^{\circ}$, at $25^{\circ} \mathrm{C}$ for the reaction in which urea is formed from $\mathrm{NH}_{3}$ and $\mathrm{CO}_{2}$.

$2 \mathrm{NH}_{3}(g)+\mathrm{CO}_{2}(g) \longrightarrow \mathrm{NH}_{2} \mathrm{CONH}_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(l)$

The standard entropy of $\mathrm{NH}_{2} \mathrm{CONH}_{2}(a q)$ is $174 \mathrm{~J} /(\mathrm{mol} \cdot \mathrm{K})$. See Table 19.1 for other values.

PROBLEM STRATEGY

The calculation is similar to that used to obtain $\Delta H^{\circ}$ from $\Delta H_{f}^{\circ}$ values.

The "Step-by-Step Explanation" refers to a detailed and sequential breakdown of the solution or reasoning behind the answer. This comprehensive explanation walks through each step of the answer, offering you clarity and understanding.
Our explanations are based on the best information we have, but they may not always be right or fit every situation.
The blue check mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Already have an account?

Question: 19.10

Calculating ΔG° and K at Various Temperatures a. What is ΔG° at 1000°C for the following reaction? CaCO3(s) ⇌ CaO(s) + CO2(g) Is this reaction spontaneous at 1000°C and 1 atm? b. What is the value of Kp at 1000°C for this reaction? What is the partial pressure of CO2? PROBLEM STRATEGY a. Calculate ...

a. From Tables 6.2 and 19.1, you have  \beg...
Question: 19.5

Calculating ΔG° from Standard Free Energies of Formation Calculate ΔG° for the combustion of 1 mol of ethanol, C2H5OH, at 25°C. C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(g) Use the standard free energies of formation given in Table 19.2. PROBLEM STRATEGY Calculate ΔG° from ΔG°f values, similar to the way ...

Write the balanced equation with values of ...
Question: 19.4

Calculating ΔG° from ΔH° and ΔS° What is the standard free-energy change, ΔG°, for the following reaction at 25°C? N2(g) + 3H2(g) → 2NH3(g) Use values of ΔH°f and S°, from Tables 6.2 and 19.1. PROBLEM STRATEGY Calculate ΔH° and ΔS°, then substitute these values into ΔH° TΔS° to obtain ΔG°. ...

Write the balanced equation and place below each f...
Question: 19.9

Calculating K from the Standard Free-Energy Change (Net Ionic Equation) Calculate the equilibrium constant Ksp at 25°C for the reaction AgCl(s) ⇌ Ag^+(aq) + Cl^-(aq) using standard free energies of formation. PROBLEM STRATEGY This is similar to the preceding example, except that you must first ...

You first calculate \Delta G^{\circ}[/latex...
Question: 19.8

Calculating K from the Standard Free-Energy Change (Molecular Equation) Find the value of the equilibrium constant K at 25°C (298 K) for the reaction 2NH3(g) + CO2(g) ⇌ NH2CONH2(aq) + H2O(l) The standard free-energy change, ΔG°, at 25°C equals 13.6 kJ. (We calculated this value of ΔG°=ΔH°-TΔS° just ...

Substituting numerical values into this equation, ...
Question: 19.7

Writing the Expression for a Thermodynamic Equilibrium Constant Write expressions for the thermodynamic equilibrium constants for each of the following reactions: a. The reaction given in the chapter opening, 2NH3(g) + CO2(g) ⇌ NH2CONH2(aq) + H2O(l) b. The solubility process, ...

a. Note that \mathrm{H}_{2} \mathrm{O}[/lat...
Question: 19.6

Interpreting the Sign of ΔG° Calculate ΔH° and ΔG° for the reaction 2KClO3(s) → 2KCl(s) + 3O2(g) Interpret the signs obtained for ΔH° and ΔG°. Values of ΔH°f (in kJ/mol) are as follows: KClO3(s), -397.7; KCl(s), -436.7. Similarly, values of ΔG°f (in kJ/mol) are as follows: KClO3(s), -296.3; KCl(s), ...

The problem is set up as follows:  \begin{...
Question: 19.2

Predicting the Sign of the Entropy Change of a Reaction a. The following equation represents the essential change that takes place during the fermentation of glucose (grape sugar) to ethanol (ethyl alcohol). C6H12O6(s) → 2C2H5OH(l) + 2CO2(g) Is S° positive or negative? Explain. b. Do you expect the ...

When liquid $\mathrm{CCl}_{4}$ evapor...