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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: drummerchic00 on October 24, 2004, 03:21:19 PM

Title: Specific heat
Post by: drummerchic00 on October 24, 2004, 03:21:19 PM

PLZ help me.
If 13.34 g of an unknown substance loses 40.8 J of heat in cooling from 50.0 degrees Celsius to 43.0 degrees Celsius, what is the specific heat of the unknown?
Plz explain to me how to find the answer

Title: Re:Specific heat
Post by: Donaldson Tan on October 26, 2004, 02:51:44 PM

specific heat refers to specific heat capacity, ie. the amount of heat needed to raise the temperature of a unit amount of subtance by one unit temperature. Its SI unit is J.Kg^-1K^-1

Using Q = mc(dT) where
Q: heat applied
m: mass of substance
c: specific heat capacity
dT: change in temperature

-40.8J = (13.34 x 10^-3 kg) X c X (43 - 50 K)

rearrange the above equation to solve..