Hi, I am doing an experiment and i have to calculate the heat gained or lost.
In the reaction i dissolved 200g solid NaOH into water and took the initial temp of the water and then after the NaOH was dissolved. My initial temp was 20 degcelcius and my final temp was 22 degcelcius.
I used the equation deltaH= m*c*deltaT
so i plug in DeltaH= 200g*0.00418kJ/gdegc*22degcel
DeltaH= 18.392
since 5.5g NaOH 5.5/40=0.1375
18.392/0.1375= 133.76
What i am confused about is, what temp am i supposed to use, 20degcel, 22degcel or -2degcel??
In the next question it says to use deltaH=m*deltaT*Q to find the heat lost or gained, isnt this what i found in the above question? Whats the difference between the two??
Can someone please explain this to me cuz i am lost.
Thanks