Calculating the Energy Needed to Heat Magnesium: A Challenge!

[davidray]

Any help on this quistion would be greatly appreciated. I have no idea ho to answere it, and can't find anything in my nothes or books anywhere.

The temperature-dependent molar specific heat capacity at constant pressure of many substances is given by: c =a+2bT−cT^−2

For magnesium, the numerical values of the constants are: a=25.7, b=3.13x10^-3, c=3.27x10^5

where c has units J/Kxmol

Calculate the energy required to raise the temperature of 15g of Megnesium from 30 C to 300 C.

I have tried using the formula to qenerate a specific heat capacity for each temperature, but just seem to get crazy numbers that don't make any sense!

Thanks for the help!

 

[NascentOxygen]

When S.H is a constant, c, then energy=c x delta T

which looks like what you'd get from integral of c from T1 to T2

So try integral of c from T1 to T2 where c is a function of T.