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April 22, 2026, 07:43:58 am
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Author Topic: Clarification  (Read 858 times)  Share 

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methodsboy

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Clarification
« on: August 18, 2009, 06:45:48 pm »
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hey guys : for the following question, how do you tell if the reaction is endo or exo thermic?

The equation for dissolving crystals of ammonium chloride in water at SLC is:
NH4Cl(s) + H2O  NH4+(aq) + Cl–(aq);  H = 15.15 kJ mol–1

#the reason im asking is cause the change in H doesnt have a -ve or +ve in front of it.
Thankyou
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TrueTears

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Re: Clarification
« Reply #1 on: August 18, 2009, 06:47:27 pm »
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If no sign you assume it has a + in front of it, hence it is endothermic.
« Last Edit: August 18, 2009, 06:58:03 pm by TrueTears »
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methodsboy

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Re: Clarification
« Reply #2 on: August 18, 2009, 06:49:07 pm »
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Quote from: TrueTears on August 18, 2009, 06:47:27 pm
If no sign you assume it has a + in front of it, hence it is exothermic.
okay thanks.
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methodsboy

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Re: Clarification
« Reply #3 on: August 18, 2009, 06:55:43 pm »
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Quote from: TrueTears on August 18, 2009, 06:47:27 pm
If no sign you assume it has a + in front of it, hence it is exothermic.
sorry but i recall if change in H is +ve;  it's an endothermic reaction not exothermic.
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TrueTears

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Re: Clarification
« Reply #4 on: August 18, 2009, 06:57:53 pm »
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lol true, soz for typo
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PhD @ MIT (Economics).

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methodsboy

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Re: Clarification
« Reply #5 on: August 18, 2009, 06:59:01 pm »
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