×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*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.

Students Click Here

Jobs

sodium thiocyanate solution

sodium thiocyanate solution

sodium thiocyanate solution

(OP)
Hi,

Im presently working on a process of making solution of NaSNC-water in a large tank.  For the design purpose, I must determine the heat loss when the NaSNC will be added to hot water.  Do anybody know if this will create a endothermic reaction, like other sodium product.

RE: sodium thiocyanate solution

grandmanitou,

Heat of formation of aqueous NaCNS is -160.06 kJ/mol (Ref Perry's 7th Edn)
Heat of formation of crystal NaCNS is -167.22 kJ/mol (Ref Perry's 7th Edn)

Heat of dissolution of NaCNS(s) --> NaCNS(aq) is sum of products minus reactants

dH = -160.06 - (-167.22) = +7.16 kJ/mol

As dH is +ve then the dissolution of NaCNS(s) is endothermic as you suggested.  From here you can use the total moles in solution to determine the total energy required to drive dissolution of NaCNS and from here determine the temperature drop in your solvent (water in this case).

Hope this answers your query.

Cheers

RE: sodium thiocyanate solution

(OP)
Hey thank you,
I did not think I would get a good anwser that fast!

RE: sodium thiocyanate solution

Great answer, Holiday. Strictly speaking, heat of solution is a function of concentration, but your method provides the heat of solution at infinite dilution, which is the worst-case scenario anyway!

Fran McConville
author of the Pilot Plant Real Book
www.pprbook.com

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.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources