Homework SourseStandard thermodynamic quantities for selected substances at
Standard thermodynamic quantities for selected substances at 25C
Part A:
What is the value of Hf for the formation of 1 mol of RbCl(s)?
Express the energy to four significant figures and include the appropriate units.
Part B
Enter the chemical equation for the formation of Pb(NO3)2(s) from its respective elements in their standard states.
Express your answer as a chemical equation. Identify all of the phases in your answer.
| Substance | Hf(kJ/mol) |
| Rb(s) | 0.0 |
| Rb(g) | 80.9 |
| Cl(g) | 121.3 |
| Cl2(g) | 0.0 |
| RbCl(s) | 435.4 |
| Pb(s) | 0.0 |
| Pb(g) | 195.2 |
| Pb(NO3)2(s) | 451.9 |
| N(g) | 472.7 |
| N2(g) | 0.0 |
| O(g) | 249.2 |
| O2(g) | 0.0 |
| O3(g) | 142.7 |
Solution
Part A
Enthaply of formation of RbCl(s) = -435.4 kJ/mol
Part B
Pb(s) + N2(g) + 3O2(g) ------------> Pb(NO3)2 (s)
