Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Aerosion on April 12, 2006, 09:49:23 PM
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Okay, let me just write down the question I'm looking at first.
"When a 6.50g sample of solid sodium hydroxide dossolves in 100.0 g of water in a "coffee cup" calorimeter, the temperature rises from 21.6 degrees C to 37.8 degrees C. Calculate the change in heat (the letter H with a triangle to the left of it) for the solution process:
NaOH(s) -> Na+(aq) + OH-(aq)
Assume that the specific heat of the solution is the same as that of pure water.
Okay, so I know that you have to turn degrees Celsius into Kelvins, which brings it up to 294.6K and 310.8K. And the specific heat of water is 4.184 J.g-1.K-1. However, I do not know how to apply that to the chemical equation that was presented in the equation.
I know this is my first post, and some forums look down on that (or so I hear, I dunno, I don't spend much time in forums). Please, though. I do need the help. Thanks.
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Enthalpy can be calculated from mass of contents x specific heat of contents x temperature change
q = m x S x dT
It is good practice to convert temperatures to Kelvin, however in this case as you are interested in the change in temperature it gives the same numerical result whether you use celcius or Kelvin.