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Topic: Chemistry Volume Question  (Read 3992 times)

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Offline alanjz

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Chemistry Volume Question
« on: March 30, 2013, 11:25:07 PM »
When MgO reacts with H2O at 25 degrees C and 1 atm, the volume change is 04.6 mL*mol^-1.
MgO(s) + H2O (l) --> Mg(OH)2 (s)
What is the value of delta H - delta E for this reaction?
(a) -4.7x10^-1 J*mol^-1
(b) -4.7x10^2 J*mol^-1
(c) 4.7x10^2 J*mol^-1
(d) 4.7x10^-1 J*mol^-1

I'm pretty sure it has something to do with work and -PdeltaV but I don't know how to proceed. Like I tried: -(1)(-4.6*10^-3).
« Last Edit: March 30, 2013, 11:44:47 PM by alanjz »

Offline Stovn0611

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Re: Chemistry Volume Question
« Reply #1 on: March 31, 2013, 12:03:14 AM »
Do you know of any formulas relating delta H, delta E, and work?

Offline alanjz

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Re: Chemistry Volume Question
« Reply #2 on: March 31, 2013, 12:14:02 AM »
isn't it dE=dH+w so dH-dE=-w=-(-PdV)=(1)(4.6x10-3)?

Offline Stovn0611

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Re: Chemistry Volume Question
« Reply #3 on: March 31, 2013, 12:59:40 PM »
is (1 atm)(4.6*10^-3) measured in the correct units though? You might need to do a conversion since 1 L*atm =/= 1 J

Offline alanjz

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Re: Chemistry Volume Question
« Reply #4 on: March 31, 2013, 04:35:50 PM »
ah so I need to multiply that by 101.3 thanks a lot!

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