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### Topic: Finding the Enthalpy change lab  (Read 2133 times)

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#### Howdoidothat

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##### Finding the Enthalpy change lab
« on: October 25, 2012, 07:21:21 PM »
I did this lab in school the other day and now I'm analyzing my data. The goal of my lab was to react NaHCO3 and Na2CO3 seperately in 2.00 mol of HCl. Because I need to use Hess's law to figure out the enthalpy change in

2NaHCO3 (s)  ->   Na2CO3(s)   +   H2O(l)   +   CO2(g)

So I've found my change in temperature, and mass of HCl, but how do I find out the heat capacity of the HCl so I can figure out Q? In Q = mc∆T.

Or is there another way to do this?

Thanks for your help.

#### Sophia7X

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##### Re: Finding the Enthalpy change lab
« Reply #1 on: October 26, 2012, 10:53:05 PM »

So I've found my change in temperature, and mass of HCl, but how do I find out the heat capacity of the HCl so I can figure out Q? In Q = mc∆T.

You don't need the heat capacity of HCl. You just need water's Cp.

Remember the zeroth law of thermo?

qgained = -qloss

For example, if the surrounding water in a calorimeter lost 50 kJ, that means the system gained 50 kJ.
Entropy happens.