# chemistry

posted by
**Pyrgus** on
.

Can somebody please help me with this question? That'd be great. Thanks!

Determine the amount of heat needed in the following:

the number of calories to heat 25 grams of water from 22 degrees celcius to 44 degrees celcius.

Q= m c deltaTemp

= 25g*1cal/gC*(44-22)C

=25*22 calories. If you want it in other units, either convert, or use the specific heat in those units.

Thank you! I have a problem that asks for the number of joules. Should I do it in calories first and convert it to joules?

As Bob Pursley pointed out to you in his post, you may use 1 cal/g*C, then convert to Joules knowing that 1 cal = 4.184 joules OR you may use 4.184 joules/g*C in place of the 1 cal in the calculations (for specific heat) of q = mcdeltaT and get the joules directly.