Question

Urea (NH2CONH2), an important nitrogen fertilizer, is produced industrially by the following reaction:

2NH3(g)+CO2(g)→NH2CONH2(aq)+H2O(l)

Given that ΔG∘ = −13.6 kJ/mol, calculate ΔG at 25∘C for the following sets of conditions

Part A

50 atm  NH3, 50 atm  CO2, 4.0 M  NH2CONH2

Express the free energy in kilojoules per mole to two significant figures.

Part B

8.0×10⁻² atm  NH3, 8.0×10⁻² atm  CO2, 1.0 M  NH2CONH2

Express the free energy in kilojoules per mole to two significant figures.

Part C

Is the reaction spontaneous for the conditions in Part A and/or Part B?

spontaneous for the conditions in both parts.

nonspontaneous for the conditions in both parts.

spontaneous for the conditions in Part but nonspontaneous for the conditions in Part B.

spontaneous for the conditions in Part B but nonspontaneous for the conditions in Part A.

Answer 1

A )Equati on: 2NH3 (g)+CO2 (g)-NH CONH2 (aq) +H20(1) Temperature,T- 298K Gas constant, R 8.314 JK-mol-1 Free energy change, Q NH, CONH (-13.6 kJmol) +8.314x10 Jmol1x(298K)In (50) (50) = (-13.6 kJ/mol)-(-25.6 kJ/mol) -39.2 kJ/mol--39 kJimol [NH CONH2 (-13.6 kJ/mol)-(8.314×10-3 JKrmol-1)×(298K)1n (0.08) (008) - (-13.6 kJ/mol) +(18.8 kJ/mol) 5.2 kJ/mol C) Since the value of AG comes out to be negative in part A, spontaneous for the conditions in Part Abut nonspontaneous for the conditions in Part B