A/S Chemistry URGENT PLEASE READ!!!

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supreme
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#1
Report Thread starter 17 years ago
#1
Basically the book says the answer is -59.1 kJ mol-1 and I can only get up to about 58. What am I doing wrong??

The question is the attachment.
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john !!
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That's pretty close, due to rounding errors and inaccurate reading of the graph probably. Neutralisation is usually exothermic so stick a negative sign on the end and you're alright.
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Ralfskini
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The book is wrong. You're answer is actually more accurate. The enthalpy of neutralisation values are all approximately -56KJ/mol
because they can be represented by the same ionic equation. (H+ + OH- ---> H2O). I did your question and got 56.8 as the answer so your answer is ok.
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john !!
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So that applies to weak and strong acids as well, because it's all 1 mole of water being made.
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etomac
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usually in exam their mark scheme will say 55-60 etc...
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Ralfskini
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(Original post by mik1a)
So that applies to weak and strong acids as well, because it's all 1 mole of water being made.

Well, the value is different for weak and strong acids but not as different as you may think. The difference in enthalpy of neutralisation between strong and weak acids only differs by about 1.7KJ/mol
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supreme
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#7
Report Thread starter 17 years ago
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Thanks everyone, it is good to know I am right
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