Heat of Neutralization

[evie'sessencecenolour]

Hello, we did an experiment of heat of neutralization.

The objective is to calculate the molar heat of neutralization

we are using calorimeter to determine the heat transferred and hence the heat of neutralization, DeltaH ( rxn)

we have

2.00M NAOH and 2.00M HCL . and collected 25 mL of each solution.

My question here is how do you calculate the above? I need a gerneal sense of idea of what to do, and it's due tomorrow. I'm keeping my cool and calm to not freak out and so far it is working here with you people. You guys are very helpful. I also want to know for the calculations part, how do you calculate the mass and temperature if we are using 3 different trials with 13 different temperature points?

I don't know if you had any similar work to this, butI would like to know. Any help is gladly appreciated, thank you. ,

[Drake Glau]

You are always using 25mL so the mass should stay the same throughout the experiment. Especially since your reaction doesn't produce a gas. Just mass it and you get your m

You're going to be using q=mc(delta)T

Either you are given c or you might be able to just assume that it's mainly water so it would be 4.18J/gC^o

You are using a calorimeter so you will be able to see an inital T and ending T, do some subtraction and there's dT and that finishes your equation, just plug stuff in and get a number.

More practical side of what you will do:

You will add your 25mL of substance A into your colorimeter. Then you will add your 25mL of substance B, quickly close the lid, making sure the thermometer is in the solution but not touching anything else but the solution. Then sit and stare at the thermometer writing down whatever temperature points you need to write down. In all honesty you only need the initial (take the temperature of the 25mL of subtance A before adding substance B) and final temperature. The final temperature will be easy to spot if you are using an automatic measuring system because it will be the max value your temperature reaches (this reaction will be exothermic). You could also just pay attention and notice when it stops going up and begins to drop also

[dessskris]

you probably have submitted your lab report but in case if anyone's doing something similar and need help:

plot a graph of Temperature over Time for each trial, plot a straight line and extrapolate the line till the time of mixing, like in the figure below:

you know I've tried to find a better graph - the line should have a negative slope and not horizontal like that. should be like in the figure below:

then find ΔH by mcΔT/n where m is the mass of the solution(s) and n is the number of mol of the limiting reagent. ΔT is found through the extrapolation before, and c is usually assumed to be the specific heat capacity of water.

[Lola234364]

On 1/27/2012 at 3:23 AM, dessskris said:

you probably have submitted your lab report but in case if anyone's doing something similar and need help:

plot a graph of Temperature over Time for each trial, plot a straight line and extrapolate the line till the time of mixing, like in the figure below:

you know I've tried to find a better graph - the line should have a negative slope and not horizontal like that. should be like in the figure below:

then find ΔH by mcΔT/n where m is the mass of the solution(s) and n is the number of mol of the limiting reagent. ΔT is found through the extrapolation before, and c is usually assumed to be the specific heat capacity of water.

Excuse me, what is the name of the program you used for the graph?