Chemical Forums
Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: nlb149 on September 03, 2009, 01:18:56 PM
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The molar heat capacity CP, m of SO2(g) is described by the following equation over the range 300 K < T < 1700 K:
Cp,m /R = 3.093 + 6.967 x 10^-3 T/K - 45.81 x 10^-7 T^2/K^2 + 1.035 x 10^-9 T^3/K^3
In this equation, T is the absolute temperature in Kelvin. Theratios ensure that CP, m has the correct units. Assuming ideal gas behavior, calculate q, w, delta U, and delta H if 2.25 mol of SO2(g) is heated from 45.5° to 1285°C at a constant pressure of 1 bar. Explain the sign of w.
okay so I know that q = delta H = nR integral of Cp dT from T1 to T2. I did this and got 1.45 x 10^5 Joules for delta H which according to the back of the book is right. I'm having trouble taking that and finding delta U or w. Any ideas?
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Do you know the definition of ΔH (that relates it to ΔU)? What equations do you know for w?
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:delta: H = :delta: U + :delta:(PV) and U = q + w are the only ones I know.
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:delta: H = :delta: U + :delta:(PV) and U = q + w are the only ones I know.
Those are the ones to use (also, you need to use the ideal gas law).