The specific heat capacity, or simply specific heat (C) of a substance is the amount of heat energy required to raise the temperature of one gram of the substance by one degree Celsius. Heat energy is usually measured in Joules ("J") or calories ("cal").
The variables in the equation q = mCDeltaT mean the following:
" let:" q="heat energy gained or lost by a substance" m="mass (grams)" C="specific heat" DeltaT="change in temperature"
Note that DeltaT is always calculated as "final temperature "-" initial temperature", not the other way around.
Therefore, you can look at that equation like this if it helps:
"heat energy gained or lost by a substance"=("mass")("specific heat")(DeltaT)
Example
How much heat energy is required to raise the temperature of "55.0g" of water from "25.0"^@"C" to "28.6"^@"C"? The specific heat of water is "4.18""J"/"g"^@"C". This is a very well known specific heat value and will frequently show up in specific heat questions.
Unknown: q in Joules ("J")
Known/Given:
specific heat of water (C) = "4.18""J"/"g"^@"C"
mass of water = "55.0g" DeltaT = "28.6"^@"C"-"25.0"^@"C" = "3.6"^@"C"
Equation: q =mcDeltaT
Solution: q="55.0g" xx "4.18""J"/"g"^@"C"xx"3.6"^@"C" q = "827.64""J", which rounds to 8.28xx10^2"J" due to significant figures.
