heating curve

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004253593
Posts: 218
Joined: Fri Sep 20, 2013 3:00 am

heating curve

Postby 004253593 » Sat Jan 18, 2014 12:45 pm

How do you know how steep to make the slopes in a heating curve and how long/short to make the lines??

104277942
Posts: 161
Joined: Fri Sep 20, 2013 3:00 am

Re: heating curve

Postby 104277942 » Sat Jan 18, 2014 9:38 pm

ANSWER:

The slopes of the heating curve depend on the heat capacity of the solid, liquid and gas. The higher the heat capacity the more resistant the substance is to heat. If the slope is super steep, that means the substance's heat shot up and it was able to gain heat quickly because it has a low heat capacity. If the slope is NOT steep and spreads out nearer to a horizontal line, that means the heat of the substance is rising slowly because the substance is able to resist heat because of its high heat capacity.

As for the length of the lines of fusion and vaporization, depending on how many kJ/mol it takes for the phase changes is how long you make the lines. For example, on page 261, the solid melting takes 6.01 kJ/mol and the line is short as compared to the liquid vaporizing (40.7 kJ/mol) which requires a lot more and has a longer line.

004253593
Posts: 218
Joined: Fri Sep 20, 2013 3:00 am

Re: heating curve

Postby 004253593 » Sun Jan 19, 2014 2:26 pm

Thanks- so basically the higher the heat capacity (the larger the number) the less steep the slope is

104277942
Posts: 161
Joined: Fri Sep 20, 2013 3:00 am

Re: heating curve

Postby 104277942 » Sun Jan 19, 2014 4:46 pm

Yup!


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