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| Learn: psychology Tinal I Quiz et Classical Study Music | Mozart OWLv2 I Onine

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Question

| Learn: psychology Tinal I Quiz et Classical Study Music | Mozart OWLv2 I Onine teaching and learnin..+ Week 15: Review Questions Question 11 pt Question 2 Question 3 Question 4 Given the following information: Energy of sublimation of Na(s)-97 kJ/mol Bond energy of HF 565 kJ/mol Ionization energy of Na(g) = 496 kJ/mol Electron affinity of Fg)--328 kWmol Lattice energy of NaF(s)920. kJ/mol Bond energy of H2 432 kJ/mol Question 5 1 pt Question 1 pt Calculate the net change in energy for the following reaction: 2Na(s) +2HF(g) 2NaF(s) .+ H2(g) kJ Submit Answer Try Another Version item attempts remaining Progress: 1/6 items Due Dec 7 at 11:55 PM PreviousNext Finish Assignment Email Instructor Save and Exit Cengage Learning | Cengage Technical Support

Explanation / Answer

Given the following information:

Energy of sublimation of Na(s) = 97 kJ/mol

Bond energy of HF = 565 kJ/mol

Ionization energy of Na(g) = 496 kJ/mol

Electron affinity of F(g) = –328 kJ/mol

Lattice energy of NaF(s) = –920kJ/mol

Bond energy of H2 = 432 kJ/mol

Calculate the net change in energy for the following reaction:

2Na(s) + 2HF(g) 2NaF(s) + H2(g)

2 of moles Na(s) ------> Na(g) sublimation = 2 x 97 kJ/mol = 194 kJ/mol
2 of moles Na(g) ----> Na+(g) + e- Ionization energy Na = 2 x 496 kJ/mol = 992 kJ/mol

2 mole of H-F bonds = 2 x 565 kJ/mol = 1130 kJ/mol

2 mole of F(g) + e- ----> F- Electron affinity F = 2 x (-328kJ/mol ) = (-656kJ/mol)
2 mole of Na+(g) + F-(g) ----> NaF(s) Lattice energy = 2 x (- 920kJ/mol ) = (-1840 kJ/mol)

Bond energy of H-H = 432 kJ/mol

Therefore, the net change of the reaction = (194 + 992 +1130 - 656 -1840 + 432 )kJ/mol = (+252 kJ/mol)

.i.e. the reaction endothermic