×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Variation of ph value of water with temperature

## Variation of ph value of water with temperature

(OP)
Dear sir,
I would like to know the variation in ph value of water with temperature.
Mehaboob.P.K

### RE: Variation of ph value of water with temperature

Don't have a graph handy, but the neutral point is ~5.5 at 300 deg C, IIRC.

### RE: Variation of ph value of water with temperature

The dissociation constant for water increases with T (Log KW becomes less negative) according to

Log KW = -4470.99/T + 6.0875 - 0.01706 T

where T is degrees K, and pH = -0.5 x Log KW.
For 573 K, this equation gives pH = -5.7 cf. the ~5.5 value given by Metalguy.
Source: M. Whitfield, in Chemical Oceanography, J. P. Riley and Skirrow, Eds., Vol. 1, 2nd ed., Academic, New York, 1975, pp. 44-171. Cited by
http://antoine.frostburg.edu/chem/senese/101/acidbase/faq/temperature-dependence-Kw.shtml#Whitfield

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!