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Molar heat of combustion vs. Molecular weight. (1 Viewer)

How did you plot your graph ?

  • Plotted values as crosses and used line of best fit.

    Votes: 46 48.9%
  • Plotted values as crosses and used curve of best fit.

    Votes: 7 7.4%
  • Plotted values as crosses and did not use a line or curve of best fit.

    Votes: 4 4.3%
  • Plotted values as dots and used line of best fit.

    Votes: 25 26.6%
  • Plotted values as dots and used curve of best fit.

    Votes: 4 4.3%
  • Plotted values as dots and did not use a line or curve of best fit.

    Votes: 8 8.5%

  • Total voters
    94

Armenikum

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Shrikar said:
I was talking about the question which asked why the value was less than the theoretical value, not what the value of the molar heat of combustion of 1-propanol.
Wernt the units already on the x-axis?
 

RaymondAllotta

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no they wernt allready on the x axis - u would have been expected to write them next to the "Molecular Weight" Title - and they were g/mol.

In the little table they had at the top of the page where the values of the molar heat of combusion were given for the other alkanols they also listed the name of the unit for molecular weight, so i dont see how anyone could have not known.
 

bmwz4

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i got 1300, is that wrong ppl? my graph was a bit weird and very small lolol
 

Kmara2nv

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LMAOOOOOO i was doing a line of best fit and it lookd fkd so i done a column graph for the fuck of it lollll still showd the difference in the wiehgt and shit but comlumn graph lolllllll oh wellll only worth 3 marks shuld still get marks for the right increments and shit
 

angelbird72

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I had gmol^-1 and 1350 for propan-1-ol and used incomplete combustion because of lack of oxygen as my reason.

I found that my graph worked out as a straight line through all of my points, and I started at meth.

The only problem with mine there, I think, is that instead of using 200 increments up the y axis like a normal person, I used increments of 180. It still worked and all, it's just that I know that when they mark they have a clear sheet that they lay over your graph and mark according to whether it matches. So mine would be different to everyone elses scale-wise, and I'm hoping it's clear how I did it.

It annoys me because a lot of times I do things like that that seem obvious to me, and then I get my test back and I have to go to the teacher and explain how I did it to get the marks I deserve, and you can't do that with this test.

And scabbing marks is one of my most valuable talents!
 

philipadams123

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i thot that incomplete combustion would be incorrect, as the lab vlaues incorporate incomplete combustion into their energy values, as even the incomplete combustion cycle produces energy, and all alkanols burn with a certain percentile incompletion. so i was stumped so i said energy was absorbed by the beaker as it entered the water :S
 

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