I am currently in the process of writing up my AS coursework investigation of finding the specific heat capacity of Aluminium, and am a bit stuck at explaining some of my results.

My results for the SHC of Aluminium are lower than the published values.

My value: 700.93 JKgC

Published: 918 JKgC

I expected my result to be higher due to heat loss to surroundings, but why has my calculated value come out lower?

Here are the calculations just to make sure i've done everything right:

Current = 1.64

Voltage = 5.71

Time = 900

Initial Temp = 21

Final Temp = 33

Energy supplied to block = power x time

= V x I x T

= 1.64 x 5.71 x 900

=

__8427.96 J__

Energy Received by block = mass x specific heat capacity x change in temp.

specific heat capacity = (V x I x T) / (M x deltaT) JKgC

= 8427.96 / (1.002 x 12)

__Specific heat capacity = 700.93 JKgC__

So why is my result lower than published 'true' value? Please if you can provide a detailed explanation so i can get my head around this as i really did expect a higher value than the 'true' one.

Thanks for any help!