# Chemistry Question - Enthalpy change of self-ionization of water...

**URL:** <https://boards.straightdope.com/t/chemistry-question-enthalpy-change-of-self-ionization-of-water/215467>\
**Category:** Factual Questions\
**Created:** [November 26, 2003, 10:43pm UTC](https://boards.straightdope.com/t/chemistry-question-enthalpy-change-of-self-ionization-of-water/215467 "2003-11-26T22:43:19Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![pretend\_my\_name\_is\_witty](https://avatars.discourse-cdn.com/v4/letter/p/b9e5f3/32.png) [@pretend\_my\_name\_is\_witty](https://boards.straightdope.com/u/pretend_my_name_is_witty)\
**Post date:** [November 26, 2003, 10:43pm UTC](https://boards.straightdope.com/t/chemistry-question-enthalpy-change-of-self-ionization-of-water/215467/1 "2003-11-26T22:43:19Z")

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Hmm, I’ve been going through this assignment, and there’s only one question that I can’t quite see how to answer. It’s an extension one, and I want to be able to have a go at answering it.

The question is:

_How would you find the enthalpy change for the ionization of water experimentally, using standard solutions of hydrochloric acid and sodium hydroxide?_

I know that we can find out the enthalpy change for the neutralization of the acid and base, and can work out how many [H[sub]3[/sub]O[sup]+[/sup]] ions there are, and I’m sure it’s got something to do with the relationship; K[sub]w[/sub] = [H[sub]3[/sub]O[sup]+[/sup]][OH[sup]-[/sup]], but from there on, i’m a little bit lost.

If someone could just point me in the right direction, or give me a hint of how to tackle this one, I’d be extremely grateful.

Thankyou all;

Harry