[airyie]

[previous topic title went against the rules. Sorry ]

Um, I have this problem on my final exam study guide that concerns calories.  I tried googling it to find anything related, and all I end up with is dieting tips.

So, I was wondering if someone could help me work it out.

How many calories are needed to change a 10.0g sample of ice at -15.0 degrees C to 0.0 degrees C?

I know the answer is 75 calories, but I am unsure as to how to find it.

Please help. Thank You.

[Yggdrasil]

In order to calculate the heat needed to change the temperature of a substance, you need to know the specific heat capacity (or specific heat) of the substance.  The specific heat is defined as the amount of energy needed to raise the temperature of one gram of the substance by one degree Celsius.  Once you know the specific heat of your substance you just use the formula:

q = mCΔT

Where q is the amount of heat, m is the mass of your substance, C is the specific heat capacity, and ΔT is the change in temperature.

You should be able to find the specific heat of ice in any high-school chemistry textbook.  Also, your book should have additional information about specific heat and problems like this one.

[airyie]

Thank you very much for your help.  It is deeply appreciated.