DeltaH of Diluting 24% NaOH to 2% in H2O

[katchum]

Hello

I know that dissolving pure NaOH in water will generate heat. But what happens when you dilute a 24% NAOH solution with water till 2%?

Example: What is the DeltaH for 100 ml 24% NaOH solution + 50 ml H2O?

Thanks

 

[Borek]

Dilution heats are tabelarized.

 

[katchum]

That's right.

I found this nice table: http://www.pioneercompanies.com/customers/tech/data/naoh/ENTHALPY.pdf

You just draw a line between your solutions and you can see the final temperature.

 

[GCT]

That's not the correct. The following outlines the correct procedure

http://photos1.blogger.com/blogger/4345/3405/1600/NaOH solution calc.gif

Katchum , were you actually asked to calculated the enthalpy of dilution?

 

[katchum]

What's wrong with my method? I was asked to calculate the final temperature of the solution.

Additionally, this is the method described by the company itself:

http://www.pioneercompanies.com/customers/tech/data/naoh/DILUTION%20OF%20SODIUM%20HYDROXIDE%20SOLUTIONS.pdf

What I don't understand is, the two curves aren't the same, or am I not seeing right? There is a flattening of the curve close to 0 % for low temperatures.

The minima aren't the same either.

(as for the enthalpy of dilution, I would substract the initial and end enthalpies with each other and that's the answer)

 

[GCT]

Your method is two steps , the actual method consists of three steps and three independent variables for a dilution ; first composition , water , and the desired composition.