CHSHW 02/28/18 This is a Numeric Entry question/Its worth 2 points/You have unli

Question

CHSHW 02/28/18 This is a Numeric Entry question/Its worth 2 points/You have unlimited attempts/There is no attempt penalty 11 Question 2 points See page 247 Copper has been used for thousands of years either as a pure metal or in alloys.Itis frequently used today in the production of wires and cables Copper can be obtained through smelting or recycing, Determine the energy associated with each of these processes in order to recycle 121 mol Cu. The smeiting of copper occurs by the balanced chemical equation where ncois -155 umol. Amme the process of recycling eopper is simplhed to just the melting point of Cuis 10845C withh-130 kimoland a molar heat capacity.cps-245olc meltingofthe solidCustarting at 25C The ' 1st attempt 11:28 > A SDFGH J B. Do we need to lob hi.. hous monu Lab U-

Explanation / Answer

For the given reaction,

CuO(s) + CO(g) ---> Cu(s) + CO2(g)

Part A) Enthalpy of reaction,

dHorxn = dHof(products) - dHof(reactants)

Taking dHof values from literature for CO (-110.5 kJ/mol), CO2 (-393.5 kJ/mol), Cu (0 kJ/mol) and CuO )-155 kJ/mol),

dHorxn = (0 - 393.5) - (-155 - 110.5) = -128 kJ/mol

we have,

moles of Cu = 1.21 mol

therefore,

Total enthalpy change dHorxn (kJ) = -128 x 1.21 = -154.88 kJ/mol

Part B) Energy for recycling copper = energy for melting + energy for fusion

So,

Energy = mCpdT + mdHfus

taking m (moles Cu), Cp (heat capacity), dT (change in temperature) we get,

energy for recycling = [1.21 x 24.5 (1084.5 - 25)/1000] + (1.21 x 13.0)

                                 = 47.14 kJ

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