# Law of quantity of heat = mass

hi for u all

i wanna ask a question in a thermochemistry about the law of

quantity of heat = mass . specefic heat . change in temp

firstly . i want to know the units of (mass ) and (heat quantity) in this law
(gm , ml , liter)..........(joules,kj)
Q: on adding 50 ml of diluted base on 50 ml of diluted acid in isolated cal. the temp. of the solution rises from 18.2 to 21.3 degree
calculate the liberated heat

thanks ...i wish u answer me quickly ....

bye

## Answers and Replies

Borek
Mentor

i want to know the units of (mass ) and (heat quantity) in this law (gm , ml , liter)..........(joules,kj)

ml and liter are not units of mass, but units of volume.

Exact units used don't matter. You need to use units of mass, units of temperature and specific heat that is expressed using these units and units of energy that you want your answer to be in.

Last edited:

thank u for your answer

but i want to know the answer of the above question
please

i answered it ...

liberated heat=100 x 4.18 x (21.3-18.2)=1295.8 j =1.2958 kj
but the answer of the book was ..1295.8 kj
so i dont know the right answer

thanks

Last edited:
Borek
Mentor

123 cBTU.

i m sorry ..i didn't understand your answer ..

Borek
Mentor

You have edited your post while I was composing mine, I have not seen your answer.

1298 Joules or 1.298 kJ it is (assuming data you have listed is correct). 1298 kJ is wrong.